University of Chicago Air Quality-Life Index

By Andy May

The University of Chicago Energy Policy Institute has come up with a new measure of air pollution they call the Air Quality-Life Index or AQLI. It uses particulate pollution concentrations to compute an index that correlates well with expected life expectancy. Particulate concentrations <10 μm (PM10) and <2.5 μm (P2.5) are utilized in the study.

The results are supported by research on the health effects of Chinese domestic and industrial coal use (see PNAS, September 26, 2017, here). The study shows that the unregulated use of coal, i.e. without any pollution controls, to heat houses in China causes much of the Chinese population to be exposed to dangerous levels of PM10. They concluded that a 10 μg/m3 increase in PM10 reduces Chinese life expectancy by 0.64 years (95% confidence interval=0.21-1.07).

The abstract of this paper reads, in part:

“This estimate is derived from quasi-experimental variation in PM10 generated by China’s Huai River Policy, which provides free or heavily subsidized coal for indoor heating during the winter to cities north of the Huai River but not to those to the south. The findings are derived from a regression discontinuity design based on distance from the Huai River, and they are robust to using parametric and nonparametric estimation methods, different kernel types and bandwidth sizes, and adjustment for a rich set of demographic and behavioral covariates. Furthermore, the shorter lifespans are almost entirely caused by elevated rates of cardiorespiratory mortality, suggesting that PM10 is the causal factor. The estimates imply that bringing all of China into compliance with its Class I standards for PM10 would save 3.7 billion life-years.”

On the University of Chicago web site here, they explain that the new AQLI measure correlates well with life expectancy and prefer it to the EPA’s “Air Quality Index” or AQI. As explained here, the AQI is determined only by the pollutant with the highest index. Pollutants checked can include PM10, PM2.5, SO2 (Sulfur Dioxide), O3 (Ozone), CO (Carbon Monoxide), and NOx (nitrogen oxides, mainly NO2). If the pollutants with a lower index are present, they are ignored. The AQI indices are computed separately, such that 100 or less meets the national ambient air quality standard and 500 is the level where significant harm to the population is expected.

The EPA describes the AQI here. They describe the details of the calculation here. The dangers of the various pollutants vary dramatically. High levels of ground level ozone are irritating to the part of the population that already has asthma or emphysema, but have not been linked to long term health problems for most people. Sulfur dioxide is an irritant, but not poisonous in small amounts.  But, carbon monoxide is a deadly poison. As the University of Chicago determined in China, PM10 concentrations are related to life expectancy. The different pollutants have different health effects, yet the AQI gives them equal weight, thus the AQI does not correlate with health risk.

Particulate pollution is strongly correlated to health risk and the University of Chicago study strongly suggests that particulate matter is the greatest current airborne environmental risk to human health. The University of Chicago provides maps of the particulate matter health risk. Figure 1 is for the world:

Figure 1: Health risk due to PM10 (source: University of Chicago)

The areas most affected burn wood and other biofuels or coal in their houses for cooking and heat. The United States, Western Europe, Canada and Australia produce much of their electricity from coal, but they use advanced pollution control equipment to remove most of the particulate matter and other pollutants from their smoke stacks, thus their air is mostly OK. Below is the University of Chicago map of the continental United States.

Figure 2: United States health risk due to particulates (source: University of Chicago)

The University of Chicago AQLI stands in stark contrast to the EPA’s AQI as can be seen from table 1. In table 1 the cities are listed in order by AQI, but the bars show the health risk from particulates. The only areas with an enhanced health risk due to particulate pollution in the U.S. are the Los Angeles and Chicago areas where the residents would live 0.5 years longer if the cities met the WHO air standards. San Diego and parts of New York City are also at some risk. The other major U.S. cities would realize no benefit.

Table 1 (source: University of Chicago)

Results and Discussion

The study, whether the conclusions are correct or not, is very useful. We are often told that all pollution is bad and the AQI makes the explicit assumption that various sources of air pollution are equally harmful. The University of Chicago attempts to measure the health effects of various pollutants and identifies particulate matter as the most harmful. I would like to see more studies of this type.

This sort of false equivalency is seen clearly in the media’s inane obsession with “carbon” pollution. They mean CO2, which is not harmful to our health and is essential for life on Earth. I should note that if one smothers due to extraordinary levels of CO2, it is the lack of sufficient oxygen that kills the person, not any CO2 toxic effects. Plus, by using the term “carbon” they erroneously conflate carbon monoxide, carbon particulates and CO2. Even the University of Chicago paper tried to conflate particulate pollution to climate change by noting that burning fossil fuels (supposedly) causes both. Yet, when we read their article a little more carefully we realize the health problem is not fossil fuel burning, but domestic coal and biofuel burning without pollution control equipment.

In the U.S., burning wood in fireplaces, dust, wild fires, effluent from diesel engines and coal-burning power plants all emit particulate matter. Wood-burning fireplaces can be particularly hazardous, since the burning takes place inside, when it is cold outside and the house is closed up, see the EPA discussion here. In cities like Chicago and Denver, many of the worst pollution days are in the winter and they are mostly due to a combination of temperature inversions and the use of wood-burning fireplaces (see the Chicago Tribune article here). Wood-burning fireplaces are wonderful on cold nights, but not very healthy, see figure 3 from the EPA.

Figure 3 (EPA)

Oddly, the climate change alarmist community, especially in Europe, has encouraged the burning of wood because they believe the CO2 and other pollution from burning wood is somehow “safer” than fossil fuels (see the BBC report here). I note the BBC pages says biofuels “may not” produce particulate pollution, this does not apply to wood, charcoal or dung, which are 90% of the biofuels used and 63.7% of the world renewable energy supply (IEA). Figure 4 shows the breakdown of fuel use according the IEA.

Figure 4 (source IEA)

As can be seen in figure 4, the relatively particulate free biofuels, biodiesel and biogases, comprise a tiny fraction of the total biofuels used. The particulate emitting biofuels comprise 63.7% of the total renewables used and a whopping 90% of the total biofuels used. The only significant particulate-free fuels used, as a percentage of our energy supply, are natural gas (22%) and hydro (2.5%).

In summary, if the University of Chicago Energy Policy Institute is correct and particulate matter is the most dangerous air pollutant, biofuels are not helping. Natural gas is the healthiest abundant alternative. Further, the study suggests that we should rank pollutants by their health risk and not treat them all as equivalent as the EPA now does. This is a welcome study and I hope it is followed up with many more assessments of risk by pollutant. Artificially making all pollutants equivalent does not help our decision making.

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110 thoughts on “University of Chicago Air Quality-Life Index

      • If the economy goes south, while I still have the resources to do so, the first thing I do will be to weld up a rocket stove that will last a few decades. Besides its other advantages, it uses way less fuel. As an efficient fuel saving heating device, it’s hard to beat a Swedish Tile Stove.

      • Clean burning wood means building a modern masonry heater. See the Masonry Heaters Association. The Rocket Mass Heater (not the Rocket Stove) is can be very clean burning. See Cob House people and Rocket Mass Heaters in Oregon (not the Rocket Stove people who are a competing group).

        Masonry heaters tested at the Brookhaven National Lab wood stove testing centre on Long Island show emission of PM2.5 of 0.6-1.5 g/kg wood fuel burned.

        Modern crossdraft coal stoves such as those I promote in Kyrgyzstan are in the range of 0.01 g/kg burned, two orders of magnitude lower than a very good (EPA 2021 compliant) mass storage heater. There is no coal stove standard in the USA. There is in China and they are in the range of 0.1 to 1.0 g/kg, well under the EPA 2021 target.

        The current Hebei stove pilot in 800,000 homes shows that the older stoves (2000-2010) can be replaced with very clean burning alternatives. In addition there is a large scale initiative to provide semi-coked coal which brings down the PM by a factor of 10 but raises the fuel cost. Modernising the designs will bring air quality up (again).

        The Mongolian National Standard is about the same as the EPA target, with the approved models well under that by a factor of 3 to 20. Those are all coal stoves.

        The idea that ‘coal makes smoke’ is erroneous. Coal smoke and wood smoke is unburned fuel. Building a better combustor burns the smoke almost entirely. This idea that one builds a smoky device and then ‘cleans it up’ is so 1970’s.

  1. U of Chicago is apparently basing their estimates of harm on PRC health statistics. How much resemblance any reports from the Chinese have to reality is unknown, but probably depends on political considerations. It is also very misleading to lump all emissions together as “pollution”.

    • Tom its pretty clear.

      On one side of the river they gave people free coal to burn for home heating
      On the other side of the river they didn’t

      The skeptical null hypothesis that burning coal in your house for heating is no health problem is BUSTED.

      for chrissake people, there has to be a limit to your stupidity.

      And you question the health data?

      How does that work? the government cooked the data to show that their own policy was stupidly killing people?

      • Steven, the study suggests life expectancy is reduced by 0.64 years in china, the worst of all offenders in the world.

        The study shows that the unregulated use of coal, i.e. without any pollution controls, to heat houses in China causes much of the Chinese population to be exposed to dangerous levels of PM10. They concluded that a 10 μg/m3 increase in PM10 reduces Chinese life expectancy by 0.64 years (95% confidence interval=0.21-1.07).

        By how much is the EPA suggesting life expectancy would be reduced in Chicago? How many lives would be lost, due to cold, in a single year if wood/coal burning was not allowed? How many billion life-years is that?

        Duncan Smith

      • Oh Mossshhher the once Great and Powerful, you say “for chrissake people, there has to be a limit to your stupidity.”

        Strange you should say that because every time you write something on these pages I think the same thing about you. Are there any mirrors in your home?

        And again I ask my question, have you always been this incoherent and wrong headed?

      • Steven

        You just stepped wa-a-ay outside your area of expertise. Calm down and learn.

        The claim that burning coal badly in a domestic situation causes health problems is uncontested, because badly burned coal produces a host of evaporated condensable hydrocarbons. The claim that it only affects half a single city is nonsense. If the prevailing winter wind is from the north, then what?

        The claim that all coal combustion produces such emissions is factually incorrect and easily demonstrated to be wrong. It is not the burning of coal that is the problem because that produces CO2 and water vapour and trace amounts of numerous elements one finds in the ground. It is the failure to burn fuel properly that is the cause of PM2.5 from wood and coal fires. It is akin to a smoky stinky diesel engined bus. We don’t blame the fuel for the failure of the old and poorly maintained bus engine to burn the fuel properly. The error in attribution is so fundamental, only a regulator could make and sustain it.

        The null hypothesis that burning coal in a home is no health problem is proposed amid a plethora of arm-waving factually deficient, oddball stats and models, cherry-picked attributions and a near vacuum of data. There is no, repeat – no, data in China on exposure, air quality, combustion emissions and mortality. It is all modeled. In fact it is 6 models deep starting with an estimate of the mass of fuel burned.

        Burning does not predict emissions.
        Emissions does not predict ambient concentrations.
        Ambient concentrations does not predict exposure.
        Exposure does not predict health impacts.
        Health impacts do not predict disease.
        Disease does not predict deaths.

        A DALY assumes that all these are predictable and attributable as a partial cause of someone’s demise.

        That is how far a “DALY” is from reality. See below.

        At the top is the Global Burden of Disease which is the basis of the EPA findings, and which are used to construct, via Integrated Exposure Response (itself, modeling BS) to arrive at a statistical construct called the Disability Adjusted Life Years. DALYs for short.

        The claim in the paper, which is utterly without foundation, is that changing a domestic fuel will create an averted DALY known as aDALY. There is no connection between a DALY and an aDALY for simple reasons. DALYs are a statistical construct for population cohorts, usually national, for people born after 1931 and who are already dead. An aDALY purports to predict the specific (meaning a particular person’s) life increase if they are exposed to ‘less of something’ without any possibility of understanding their future exposures, diet, changes in habitation, genetic susceptibility to diseases, water quality and so on. No one can predict anyone’s future IER. None. It is a nonsensical and illogical and medically unsustainable claim – that people’s lives will be extended by 0.6 years or 5 years. No one can predict anything of the sort.

        Past impacts producing DALYs are from an examination of what people born after 1931 (86 years ago) were exposed to, ate, didn’t eat, gender, age, genetic profile and so on and on. That has nothing to do with what future generations will experience nor what someone born in 2013 will experience by the year 2099.

        Other claims in the paper are fundamentally unsupportable because there is no such thing as a calculable aDALY for a population, let along an individual. For further reading see papers on GBD, DALY, IER, IHME and the Gates Foundation’s involvement in this whole mess.

        Further, the EPA declaration that all PM2.5 is equitoxic was made with the excuse that ‘we don’t know that it isn’t true’. Wow. Really high quality logic there, not. If it is true, then there would be no difference between a farmer ploughing the back 40 and someone smoking 2 packs a day. In fact, in the eyes of the EPA, they are equivalent. And that is the whole basis of the chain of models that leads to the DALYs. It is well known that cigarette smoke is much worse tham many other types of PM2.5. That is one of the few things we do know about airborne particles, having been properly researched.

      • That’s the way to teach Steve. Start by telling your students how stupid they are. Please, please tell me you don’t have children. The poor things will have multiple mental health issues.

      • Mosher’s comment was still a non sequitur, as my comment was on the reliability of any study coming out of the PRC, not whether such a study could be valid if it was accurately reported on.

      • Yet another drive by dismissive comment by Mosher, who fails again to respond to valid criticisms.

        I don’t believe any of us thinks that indoor coal fires are particularly good for our health. But they are undoubtedly a lot better then the alternative, which is freezing to death.

        The real solution of course is to provide cheap, reliable heating, either through electricity or natural gas.

        China has the good sense to know that it cannot do this with unreliable wind and solar power.

      • “Steven Mosher October 7, 2017 at 1:06 pm
        Tom its pretty clear.

        On one side of the river they gave people free coal to burn for home heating
        On the other side of the river they didn’t

        The skeptical null hypothesis that burning coal in your house for heating is no health problem is BUSTED.

        for chrissake people, there has to be a limit to your stupidity.

        And you question the health data?

        How does that work? the government cooked the data to show that their own policy was stupidly killing people?”

        Is that so, Mosher? The result is cut, dried and quantified?
        People are dying, for chrissake?

        Bullshi_!!

        “They concluded that a 10 μg/m3 increase in PM10 reduces Chinese life expectancy by 0.64 years (95% confidence interval=0.21-1.07).”

        This is obviously a result from a model, not reality. 0.64 years, with a truly absurd level of confidence!?

        Less than 1% of a person’s lifetime is conclusively proven reducing that person’s life?
        Smokers are accounted for?
        Fertilizer workers are accounted for?
        Workers handling various dust producing products are accounted for?
        Citizens raising pigeons for fun and food are controlled for?
        etc. etc.
        Just how did the researchers rigorously and thoroughly investigate every single citizen, every day, every month, every year of their lives to thoroughly vet every possible lung contamination?

        “This estimate is derived from quasi-experimental variation in PM10 generated by China’s Huai River Policy”

        “Furthermore, the shorter lifespans are almost entirely caused by elevated rates of cardiorespiratory mortality, suggesting that PM10 is the causal factor ”

        Almost!? Pure twaddle!

        More confirmation bias research where the cause is predetermined and the data and mathematics tortured until it agrees?

        Leaving us wondering about rampant stupidity gleefully displayed by global warming funding dependents.

      • Steven
        A slight misunderstanding on your part. Coal and wood are NOT burned inside an apartment for domestic heating. Domestic water heating (winter), underfloor sh!t, is supplied by the government for a fee. The subsidy would be supplied to residents in a particular area. Probably a good idea so that city residents in poorer areas don’t freeze to death.
        The coal plants, for heating water, may not be that good but that is PM in the outside air.
        I simply can’t stand China ‘bashing’ from people who have never lived here. Perhaps some have lived here for a few months and spent most of their time with foreigners.
        The study is just a nonsense and conflates deaths with population density. Good luck to them. Money for nothing and your chicks for free.

      • Let’s assume the data is correct. They still don’t state what the people on the other side of the river used to provide heat. Did they use less coal or more of some other less toxic substance? Or did they heat less and that’s what provided the health benefit? Maybe living on the welfare side of the river is bad for your health?

        They also don’t seem to have accounted for pre-existing respiratory or CV disease. Was the excess mortality spread evenly between the healthy & unhealthy groups or was it confined to those, as might be expected, with pre-existing disease?

        Finally, the health effect took 0.6 years (31 weeks) off a life of 7-8 decades. Statistically significant but clinically insignificant.?

      • Steven, the study suggests life expectancy is reduced by 0.64 years in China, the worst of all offenders in the world.

        HA, …… 0.64 years …… is equal to …… 233.6 days.

        China – (2015) – average life expectancy 75.99 years — Population – 1.371 billion

        USA – (2015) – average life expectancy 78.74 years — Population – 320.9 million

        So, with 1/4th the population, ….. far better living conditions, ….. far better nutrition ……. and far better health care, …… the US life expectancy is still only 2.75 years (+- 233.6 days) longer than China’s life expectancy.

        Is utter stupidity better than no smarts at all? Or is utter stupidity nothing more than an emotionally rewarding attribute?

      • Thank you Crispin for your informative posts.

        In Alberta, our NDP (Harpo-Marxist) government has decided to convert our coal-fired power plants to natural-gas fired, because they allege that the coal plants cause air pollution that is killing significant numbers of people. The coal plants are fitted with particulate control equipment, and our Western coal is low-sulphur.

        i fully expect that there is no measureable increase in mortality due to atmospheric pollution from coal plants. However, it is incontrovertible that Excess Winter Mortality in Canada totals 5000 to 10,000 excess winter deaths per year, and I believe, based on the evidence, that excessive increases in energy costs are a significant driver of higher winter mortality rates.

        Let’s put their coal-to-gas power conversion into perspective. I have read that one typical forest fire emits about as much air pollution as all of Alberta’s coal plants do in a year. We have about 1000 forest fires per year in Alberta – this past summer was particularly bad, with visible wood smoke all over the province.

        Our Western Canadian provincial governments have a very poor record of managing forest fires, and we have experienced significant air pollution and major destruction to several towns as a result of poor fire-management policies.

        I suspect that if our government were to invest the same dollars in sensible forest fire management and leave the coal plants as-is, Albertans would experience far fewer deaths due to air pollution..

        I also suspect that natural gas prices will increase in a few years and coal will again be significantly less expensive than gas.

        When politicians fool with energy systems, costs go up, grid reliability decreases, and real people suffer and die.

        Regards, Allan

      • Mr. Mosher’s is not a valid conclusion. This is an observational correlation study. No conclusions can been drawn about cause and effect. The same reasoning has led many to assume connections in human epidemiology that ultimately prove wrong. There are many other potential explanations for altered life expectancy of this ver small amount which may have nothing to do with airborne particulates. Direct evidence of toxicity of these particulates from reliably designed studies appears lacking.

    • Tom Halla:”How much resemblance any reports from the Chinese have to reality is unknown, but probably depends on political considerations.”. These reports (NB, the Chinese not the Chicago) don’t smell of political considerations. It seems extremely unlikely that those preparing the health stats would have even been aware of the supply of coal, and if they had then they would surely have manipulated out the result that the Chicago study found.

      Tom Halla again: “It is also very misleading to lump all emissions together as “pollution”.”. That is more like what the EPA does (they don’t distinguish between different pollutants). This study didn’t do that: It uses particulate pollution concentrations to compute an index that correlates well with expected life expectancy..

      I’m very much in favour of pollution being looked at in the way that this study does, ie. where attention is paid to pollutant-specific harm. I can’t tell if it is correct – I hope it is because to me it makes sense – but to me it doesn’t smell of political considerations or of anything else untoward for that matter. What it does tell you is that choice of fuel is relatively unimportant, what matters is how it is used. So for example, the way that the media use the term “clean coal” is quite wrong – correctly used, coal is clean.

  2. I lived in SoCal for years. Air Quality, when the winds are Southerly, is disgusting. LA region is in a constant fog of car exhaust requiring a rain storm to even see the surrounding mountains. It’s never going to change due to the topography and the need for public transportation.

    Let’s look at a real problem.

    Fight against malaria gets two new weapons
    http://www.futurity.org/targeting-malaria-parasites-1564462/

    Excerpt:
    One team of researchers from the Johns Hopkins Bloomberg School of Public Health’s Malaria Research Institute discovered a strain of bacteria that can spread rapidly and persist long-term among malaria-carrying mosquitoes. They genetically modified the bacterial strain in a way that strongly suppresses development of malaria parasites, making mosquitoes much less likely to transmit parasites to humans.

    A second team of researchers used a genetic modification to boost the immune system of malaria-carrying mosquitoes. The genetic change not only suppresses malaria parasites in the insects but also spreads quickly in a test population by changing mosquitoes’ mating preferences.

    A “Malaria Super Bug” has been reported in the news over the past couple of years. It’s a drug treatment resistant mutation. The last time(s) this occurred in the 1900s, it killed millions in Asia, India, and Africa.

    We know how ENSO changes directlly effect rainfall in Africa and thus the potential for mosquito blooms. Seems to me, a prefect Climate Modeling opportunity to predict the target for abatement strategy.

    Geneticly modifying mosquitos — what could go wrong.

    Looking forward to comments from Willis and Monckton.

    • “Particulate pollution is strongly correlated to health risk and the University of Chicago study strongly suggests that particulate matter is the greatest current airborne environmental risk to human health. The University of Chicago provides maps of the particulate matter health risk.”

      Nonsense!

    • “In summary, if the University of Chicago Energy Policy Institute is correct and particulate matter is the most dangerous air pollutant, biofuels are not helping. Natural gas is the healthiest abundant alternative. Further, the study suggests that we should rank pollutants by their health risk and not treat them all as equivalent as the EPA now does. This is a welcome study and I hope it is followed up with many more assessments of risk by pollutant. Artificially making all pollutants equivalent does not help our decision making.”

      “Biofuels” – so Biogas, used to power Fuel Cells to undercut the cost of water treatment, isn’t insightful? Well, I suppose it could be if we can change water treatment facilities to capture the fuels. They currently vent the gases.

      Coal isn’t the issue – it’s simply how we use it! Coal and its byproducts are used in thousands of products.

    • John:

      You say: “LA region is in a constant fog of car exhaust requiring a rain storm to even see the surrounding mountains.”

      Nonsense! When was the last time you were in LA?

      It hasn’t rained in six months and I have no trouble seeing the mountains 50 miles away. This is more common than not these days.

      • I was there in 1978 and returned to SoCal Orange County in 2013.

        In 1978 I lived in downtown LA for 3 months before it rained and I saw the surrounding mountains. Took a drive up to the Art Center and literately drove up out of the smog.

        Newport Beach and Irvine 2013 and 2015 respectively. The pollution pouring out of LA with southern winds was disgusting.

        Has it improved from 1978, thankfully yes but it’s realative to ones perception.

        Here’s an example:
        Catalina Island relies on rainfall for potable water. It’s surrounded by the Pacific yet doesn’t use desalination nor fuel cells.

        This is not the California of yesteryears … a CA leading innovative solutions

    • Mr. McClure must be speaking of a different Los Angeles from mine, perhaps one on another planet. The constant fog of car exhaust he speaks of is only in his imagination. I’m not sure about the rest of his comment; it may be correct. I’m certainly not eager to see anyone create a breed ot giant tsetse flies, in the manner of Dr. Akbar.

      • Thanks for the formality but John is good by me.

        “Only in my imagination”, the issue LA is topography. It isn’t going to change.

        The air pollution is because everything is spread out requiring personal transportation (cars and trucks). Car and Truck exhaust are the issue not power generation!

    • The problem isn’t care exhaust, it’s every other economic activity that is taking place in the valley.
      Everything from bakers baking bread to painters painting houses.
      Cars have gotten so clean in CA that the air exiting the exhaust is cleaner than before it entered the car.

      • “Cars have gotten so clean in CA that the air exiting the exhaust is cleaner than before it entered the car.”

        Hopefully the air entering the engine is cleaner! Smog checks don’t make the exhaust cleaner than the air unless you have a VW ; )

    • ‘False. Air pollution kills no one in China. China should clean its filthy air, but no lives will be saved. This new study is just more egregiously bad, self-debunking air quality junk science.’

  3. I’m rather surprised that the maps top out at a life expectancy loss of four years.

    One of the worst occupational hazards is particulates. link Coal is bad and gives you black lung disease. Silica is worse. Even woodworking dust is pretty gnarly. I’ve seen cases where individual workers lose decades of life.

    • Commie, four years is an average for all people in the area. Some people in the polluted areas will lose decades of life, other will lose nothing because they die of causes unrelated to air pollution.

      A four year average loss of life for everyone is a pretty high toll in my opinion.

    • CommieBob,

      It is the quartz fraction of coal dust that causes silicosis(“Black Lung.”) The actual carbon itself is relatively inert, and passes back up in the mucus the lungs constantly expel. Little if any particulate can penetrate the mucus layer in the lungs, except crystalline ones such as quartz and asbestos.

    • Decades of life can be lost by overdosing on anything which is potentially toxic through chronic over-exposure. The question is, what is the PEL of that particulate, and can engineering or practice be modified to reduce the exposure(s) to attain that?
      Good luck with the ‘practice’ part when it comes to PM10.

      Besides, they want to reduce world population in this century anyway. All they need to do is make ‘particulate-clean’ energy sources expensive enough that the majority of humanity are forced to burn anything available to extend their ‘chronic-exposure-threatened’ lives.

    • commieB

      ” I’ve seen cases where individual workers lose decades of life.”

      That is not ambient pollution, that is industrial exposure. The claims in the paper are that reducing local ambient pollution a specified amount will extend the lives of those who live there a calculable amount. That claim has no basis in science. See above.

  4. Born in Great Britain just after the end of WWII, I well remember the massive pollution that was ubiquitous over most of the country in the 1950s and 1960s.
    Even in the country, everything was black, houses were black, dry stone walls were black, even the sheep were black. As a child, one of the things that impressed me on my first holiday in Northern Scotland was that the sheep were white.

    All industry ran off coal, mostly burned in thousands upon thousands of Lancashire boilers, the smoke kicked out on Monday mornings as these boilers were lit was something to behold. Most household heating was by open coal fires, and the vast majority rail transport was pulled by coal burning locomotives too. All diesel trucks and buses emitted huge clouds of soot from their exhausts.

    I well remember the last great smog in Manchester in winter 1965, a group of us watched the fog bank coming down a long straight road, occulting each orange street lamp as it passed over it, really quite scary… When it reached the nearest street lamp, it was visible as a slanted wall travelling towards us, then that lamp disappeared too. When it reached the lamp we were standing under, it vanished, there was nothing but a dirty brown fog, you literally couldn’t see your hand in front of your face. It took me two hours to cover what was normally a ten minute walk to get home that night, involving the canal towpath and a couple of footbridges. Manchester ground to a halt for three days, no buses and no road transport even in daylight, walking a mole or so to work was a major undertaking.

    Then came the Clean Air Acts, massive building of power stations such as Drax rendered the Lancashire boilers a thing of the past and the domestic coal fires were no longer permitted to burn the smoky high sulphur bituminous coal that contributed to the smogs.

    The point of all that is to point out that I and all the other citizens of the British Isles of my generation who lived and breathed through that period when the pollution was orders of magnitude higher than now – I remember my grandmother having to take care when she hung out the washing because sometimes the rain was so acid from the sulphur that it literally burned holes in her sheets – are apparently living so much longer than the previous generations – as much as twenty or thirty years – that the date we can draw our pensions keeps going up and our longevity appears to be causing a massive and increasing load on the health and care services.

    Now, despite the much, much lower levels of pollution we are told it will substantially decrease our life expectation.

    Something somewhere doesn’t seem to add up somehow!

    • catweazle666.
      I think that what gets overlooked is the tradeoff between a higher standard of living — better transportation and better medical care that results in lowered mortality. Yes, particulates may take their toll, but a regular diet of pizza and beer will probably shave off more years than the particulates. One has to ask the question whether a rural life style of debilitating work, poor medical services, and little opportunity beyond the drudgery of surviving is better than what the urban Chinese of today have as a result of burning coal. Seldom are things black and white (unless it is white linen hung out to dry downwind of unregulated coal furnaces).

    • catweazle666

      You have described the perils of failing to burn coal properly. All that pollution was unburned evaporated volatiles and black carbon particles lofted up the chimneys. Sulphur is an inherent emission and for domestic use is controlled by using low-S coals or adding limestone to briquettes (it absorbs it). All the rest is not inherent, though it is very common to speak as if it is because most people have never seen a really clean-burning coal stove or boiler or heater. After seeing one, it is common for them to remark that they did not think this was possible, and marvel at what smokeless burning of lignite or other coal looks like.

      • “You have described the perils of failing to burn coal properly.”

        Indeed, and it was all cleaned up by the end of the 1970s by the Clean Air Acts, which wiped out the Lancashire boilers driving the steam engines powering the ubiquitous lineshafts and belts that ran the machines and replaced them with electric motors and enforced clean burning stoves, smokeless fuel and replaced many of the open fires with gas heaters burning the North Sea gas that was being introduced at that period.

        The North Sea gas also spelt the end of the gasworks producing town gas by distilling coal in the old retort houses, one of which I worked in for a short while in the mid 1960s. Built in 1874, the working conditions had not changed since the Victorians built it, incredibly hot – on the face of the retorts themselves if you spat on the catwalks it danced – and you had to be capable of breathing a mixture of ammonia liquor, carbon monoxide and coal tar vapour at elevated temperatures. Scraping the carbon deposits out of the ‘foul main’ was a task best avoided, as was rogering the producer bus main to remove the red-hot fly ash.

        Then there were the purifiers, big beds of iron oxide that the gas was passed through to remove the sulphur, When the oxide was ‘spent’ it was dug out and piled up in huge heaps so the air and rain would oxidise the iron sulphide back to iron oxide, which was what gave the old gasworks their characteristic odour.

        Ah, them were t’days, proper engineering, all steam driven too, of course!

        If modern the Elf’n’Safety brigade had ever seen what we retort house technicians had to put up with, they would have died of shock.

    • catweazle666

      Thank you for your most interesting post, I really enjoyed reading it, and I learned a lot.

      One thing we do not know is how much this pollution has contributed to shorten the average British lifespan. I see that the UK comes out at 80.7 years life expectancy in the CIA World Fact Book, and that is similar to Germany, but 1.1 years behind France.

      Germany did also have severe pollution, and it lasted longer in the east, but I think most of France has always been spared for the worst pollution. I am not saying that this proves anything, but there may be a link?

      /Jan

      • “I see that the UK comes out at 80.7 years life expectancy in the CIA World Fact Book”
        That presumably means that the UK average citizen was born around 1937, so grew up during the period during the period 1940 – 1970, when atmospheric pollution was at its worst.

        Note that when the post-war Government introduced old age pensions commencing at 60 for women and 65 for men, it was not expected that most British citizens would even reach their allotted ‘three score and ten’, far less substantially exceed it, so I imagine those pension age figures were based on experience of the British born before the war.

        It would be interesting to see a graph of life expectation versus date of birth, as it seems to me that despite all the dreadful risks caused by pollution, smoking, drinking, poor nutritional habits, pesticides, insecticides etc. we modern citizens of of the civilised West are subject to, contrary to the dire prognostications of the health and safety brigade we seem to be living longer…and longer…and longer…

      • Catweazle666, the cartoon is funny but very wrong

        Their air was not clean, they were exposed to in house air pollution from wood cooking and heating without chimneys. The poorest part of the world’s population experience the same today and it is indeed deadly.

        Their water was not pure at all. It is difficult to not pollute the water in even a small tribe. Open latrines and garbage easily leak into the wells.

        They may eat have eaten organic food, but they had no way of conserving the food so much of it was rotten.
        People did not live as long as now, but they did live past thirty. Ötzi is estimated to have been 45 when he died 5200 years ago.

        Jan​

  5. Why has my post on post-war pollution levels in the UK failed to appear, it contained nothing even remotely contentious?

    (It was resting in the spam bin,now approved) MOD

  6. What if we compare the present AQ of the US to that of 1955 – 1970?
    Can anybody post any comparisons?
    I remember air and water being much more polluted then compared to now.

    • It was. And a lot more people smoked. And diet was dominated by things like “Wonder Bread! builds strong bodies 12 ways” and other foods that stripped out nutrient then added a few back in. Formula was encouraged over breast milk for infants.
      But Medicine did advance. It got better at treating and preventing what might or does go wrong.
      I doubt many readers out there were given a smallpox vaccine. I was. Polio? etc. etc.

      My point is that, just like CO2 and CAGW, life expectancy cannot be narrowed down to just one cause of it going up or down.

  7. My colleague at EPA created the AQI back around 1978 or so. EPA was looking for an easily understandable index that would be related to the standards That had been set in 1970 for the “criteria” pollutants (PM, CO, SO2, VOCs, ozone, NO2). The standards were all set based on health studies. At the time, and still today, CO is the only air pollutant appearing on death certificates. PM had been identified in the Harvard 6-City Study as being associated with small reductions in lung capacity, but had not yet been identified with mortality. Among the VOCs on the other hand, was benzene, at the time one of the only known human carcinogens (leukemia among workers at a rubber plant). The health effects of the remaining three pollutants (SO2, ozone, NO2) were not thought to affect mortality.

    Over the following years, the EPA regs resulted in tremendous reductions in PM (from industrial processes, CO (from auto exhaust), and SO2 (from coal-fired power plants). (VOCs, NO2, and ozone have been tougher to control.) Having gone from a clean city (Seattle) to a dirty one (NYC), I am one of a multitude that can attest to the effectiveness of these standards in avoiding the Beijing situation.

    In the 80s and 90s, the Harvard 6-City Study (again) and others established a relationship between PM levels and mortality. Multiple studies of 100 cities in the US and other cities in Europe have confirmed the relationship. The actual cause of death is not solely respiratory disease, as one might think, but includes cardiovascular deaths, apparently from interfering with the signals keeping the heart pumping in an organized fashion. In the 90s, measurements were made of PM levels in homes using traditional unvented stoves and biomass (dung) fuel. Concentrations are enormously high, in the range of mg/m3 (compared to the annual PM2.5 standard in the US of 12 micrograams/m3. WHO concluded that this indoor air pollution was one of the major causes of death worldwide, at about 3 million deaths per year, mostly women and children. China attempted to solve the problem by giving 800,000 vented stoves to rural households, but apparently the people preferred the old ways and I understand the program was a failure.

    So yes, it has been accepted for a decade or more that PM is the main airborne killer, but it was hardly known in the late 70s when the AQI was developed. The AQI was adopted pretty much nationwide and did a good job for years in keeping awareness high of outdoor air pollution. But it also makes perfect sense for the University of Chicago group to use their own index, although how that differs from simply using the measured PM concentrations escapes me for the moment.

    • That Harvard 6-city study is often cited and is strongly criticised for its numerous failings. No one believes it anymore. It is now lampooned, not believed.

      The WHO made no such finding about a ‘major cause of death’. They repeated other studies in which the global burden of disease was apportioned, to cohorts already dead, to a large number of contributing factors. This is then turned into a supposed integrated exposure response for which there is little data and much speculation. That is turned into a calculation of the shortening of lives. Deaths were not attributed, but ‘premature deaths’ which means any life that did not last 86 years (the current expectation). People citing t he works of others frequently drop the ‘premature deaths’ label and write ‘deaths’ not knowing the difference between a statistically shortened life and a medically judged cause of death. Even among 100m shortened lives, there may not be a single death from air pollution. They are different things.

      The IER and IHME cookery produces numbers in the absence of facts. They attribute to all deaths a single cause, and then say, “X-causes N deaths per year” when in fact it may be that no one died from X at all.

      Your story about China is totally off-base. They have distributed more than 100,000,000 improved stoves during the 80’s and of course there was resistance in one place or another. People like traditional devices, but the effect was dramatic. It was not about reducing emissions. The driving motivation was thermal efficiency. That was achieved. In the 90’s they introduced tighter regulations about emissions and the current Hebei Clean Air Project has very tight requirements for emissions from coal stoves. It is a programme covering 800,000 homes and the approved stoves are bought by individuals it they want one. All approved stoves have 40% of the emissions of the 2005 model baseline, and far below the 1980’s models. The pollution in Beijing air comes largely from surrounding Hebei Province. Many of the models supported are cleaner than the coming EPA 2021 targets for wood stoves in the USA.

    • One has to ask why after US levels of PM have decreased so much that we have not seen improvements in the alleged health impacts. Also would like to know why the data for the six city study have not been released for independent analysis.

    • The Harvard Six-Cities Study has never seen the light of day. EPA says, “PM2.5 is toxic because Dr. Dockery says so. Nya, nya, we have his study and you don’t…”

      President Trump should have this egregious false justification for enormously expensive regulations on his list of corrections for the EPA.

  8. So how many trillions will they spend to increase the life of 5% – 10% of the population by less than a year? Then consider it increases the life by one year and that means that they will be a burden on the socialized health care system that the Socialist Progressives want increasing the cost even more.

    • Dear usurbrain.
      Very well said!
      What is the cost at the margin to Society of prolonging the life of a geriatric/pensioner/patient on life-support, and for what benefit (the latter being a topic in and of itself)?
      I do NOT want to be a drain on socialized health-care budgets just to prolong my life by a month or three. Where is the clear-thinking and political leadership on this?
      Why can’t I opt to end my days in a designated, properly designed and administered facility?
      Stand the argument on its head and do a DCF analysis taking into account Facility Costs *and* money saved by mitigating geriatric-care costs.
      Why can’t I vote for an early exit and have the geriatric-care dollars applied to my grandkids … a much better Allocation of Funds.

      • Yes, in UK smokers are a net benefit to National Health Service because they die early and pay more in tax on cigarettes than they cost. The teetotal health nuts are the real problem, lingering beyond their natural span and costing a fortune in geriatric care.

  9. Sulfur dioxide is not an extremely toxic gas. It is extremely iritating but is otherwise not particularly toxic It is used as a catalyst for chemically bonded foundry sand cores. You have it confused with hydrogen sulfide, I believe.

    • In Chem 105A, a standard experiment was to determine the molecular weight of Sulfur by burning it in contact with (IIRR) several feet of fine copper wire. This was done by about 20 students at a time, coughing and wheezing. The classroom was our hood. Yeah, it’s not toxic, but it’s irritating as hell. I believe students now have the luxury of a vented hood, but they’re paying 65 times as much tuition as I did, not counting parking fees.

    • SO2 is also quite safe at 20 ppm. There is nearly nowhere in the world that achieves a level that high.

  10. If I die a couple of days earlier just so I can enjoy a BBQ, camp fire, so be it. Life would not be complete without it. When the snow is flying, nothing like a hot wood stove in the garage. Couple of beers, steaks and everyone sitting around living life (or otherwise not).

  11. Looking at the map (figure 2) something close to 98% of the lower 48 won’t benefit from any higher AQ measures at all. I kind of doubt that.

    • I don’t. The regulations are so far into the land of diminishing returns. Too many of these studies are just bunk. Then the regulators extrapolate the bunk into nonsense. I say that we could roll back the regs to 1990 levels and *not* be able to notice the difference.

      • Good point! I got plenty of polluted air recently but you are right – stricter regulations won’t change a thing about wildfires. So on second thought the map looks more convincing now.

  12. VOODOO SCIENCE: This re-use of voodoo epidemiology based on the pure-guess, bias-based, picked-for-convenience assumption that “elevated rates of cardiorespiratory mortality” experienced north of the Huai River “suggest… that PM10 is the causal factor. “. There have been a series of these utterly unscientific, insupportable studies based on the same silly assumption — confounding heating with INDOOR coal burning (smokey homes) and ambient air quality measures. These studies totally ignore other measures of air pollution and other causes of cardiorespiratory disease — pinning the blame entirely on PM 10….with virtually no experimental support — epidemiology all the way down.

    This same Hua River nonsense is responsible for nearly every study blaming huge numbers of premature deaths on PM 10, PM2.5 etc — with no one going back to discover why the actual real world numbers don;t add up. The improvement between the dire situation in China and the Clean Air of America should show American’s totally devoid of cardiorespiratory disease — but we are not, and the crazy EPA keeps trying to “cure” cardiorespiratory disease here by mandating strictewr and sctricter PM goals, none of which improve the stats.

    Madness.

    This is a good example of how an entire field goes off the rails by basing all subsequent work on one bad study whose assumptions are the conclusion — circular science.

    • Amen. The core of the problem is this: To a man who only owns a hammer, everything is a nail.

    • PM10 doesn’t make it deep enough into the lungs to cause problems. It is only PM2.5 which is claimed to have an effect. The reason they had to use PM10 is there is virtually no relevant data available to conduct such a study.

  13. 1) Well, the EPA provides its own refutation of the “endangerment finding” by not including CO2 in the list!

    2) The Sahara is intermittently a very dusty place but comes off with a clean bill of health? The “harmattan” is a wind that carries red dust south over the southern Sahara and across the Sahel and even further south over the sea in West Africa.

    3) It is a simplistic notion that PM10 and PM2.5 abundances have a linear relationship with health effects. The lungs have cilia (hairs) that move dust collected in the lungs and trapped in the mucous with a sweeping motion upwards that pushes the mucous to the trachea where we cough it up and out of the lungs.

    https://www.quora.com/What-is-the-function-of-cilia-in-the-lungs?share=1

    In the case of smoke, and other pollution sources, the burden of constant influx can overwhelm the cilia and also, with certain materials chemically impair them leading to emphysema, silicosis, etc which is a “drowning” of the lungs in mucous and a reduction in the delivery of oxygen to the body. We did evolve with abundant dust (ice age loess (silt) blowing around and wood fires, but less chemical pollutants as in the above list.
    Studies done with asbestos pollution found that there was a synergistic factor statistically in which smokers among asbestos workers were the main population of sufferers and many non smokers were unaffected. Add wood and coal domestic fires and other stressors to the mix and the statistics may have suggested asbestos to be less harmful.

    The asbestos hysteria, which led to overly restrictive controls and outright bans of a whole range of acicular minerals, resulted in harm thresholds that were well below the levels found in natural rivers draining the Canadian Shield which abounds in a variety of metamorphic rock minerals with acicular shapes.

    I suspect that there is a higher threshold of particulates that are okay and that it is a logarithmic increase that is of interest along with compounding effects of two or more pollutants. A bit of strichnine is a medicine and a lethal dose of milk will kill you.

    • Human health response to PM2.5 is highly non-linear. An increase of 50% has nearly no effect. It is commonly said that if there is enough to cause a detectable effect, it has to be reduce by 90% to ‘fix the situation’.

      The WHO advice of 25 microgrammes per cubic metre is extremely low and not achievable I’m many countries due to, as you say, the Harmattan which I have experienced in Ibadan. Mother Nature rules!

    • in the 70’s my brother bought 50 some acres in northern VT for a Ski Lodge at a very good price . However, a woman in her mid 80’s lived on a small home on the property and she would not leave till she died. My brother did no mind as he had heard of the Asbestos scare and was sure she would not live long, thus he was willing to buy that property. The property even had a “mini” mountain of tailings from the local asbestos mine ftah could be seen from the house. Need less to say she lived till she was 97 years old. Her husband and sons even worked at the mine and she did the laundry for them. All lived to much more than 80 years old.

  14. Now that I’ve had my rank about the Huai River non-science epidemiology study, it is true that living in a constantly (or even seasonally, smokey home is not good for human’s health. No one has ever thought it was — Benjamin Franklin developed the Franklin Stove back in 1741 to help fight this problem.

    The cognitive error in all this PM 10/PM2.5 nonsense is the conviction that if a lot of smoke is bad (and it is), them even tiny itty-bitty amounts must be bad too. Current standards set by the EPA are stricter than Nature’s norms in may places — where natural particulates exceed the EPA strict standards….how in the world a locality is expected to eliminate the long-term natural norm is beyond me. Looks closely at Fig 2 in the essay — PM pollution is not found in America’s major cities — but in widely separated rural areas the Southwest and a large patch just south of the Great Lakes. Not coal country, not Los Angeles with its smog, not Denver and its smokey winters……

    Like out-of-control climate modelling creating never-to-be-seen threats, computer-enabled epidemiology creates monsters out of mild irritants.

    • Just go to the Blue Mountains in summer. All that blue haze is natural forest PM2.5. All of it.

      • Yep. The Great Smoky Mountains were called that by people who saw them (at least) 400 years ago. I remember well the smell of pine forests. I remember well the smell of meadows. All of that is ‘natural’ volatile organic chemicals. All of that undergoes photolytic conversion and some of it results in soot, even when the forest does not burn.

  15. As the pollution seems to be concentrated in cities I propose we legislate to limit their size. This can easily be done through planning/building controls. When the city reaches “max” you stop building. The smaller cities will then get the growth.

    As an associated control measure we can offer free contraceptive implants to all females over 12 years old, free abortion on demand and a plethora of contraceptive advice and free contraceptives.

    Where cities are already too big we can offer incentives for people to move to more rural areas or smaller cities, towns, etc or even to another country (export the problem).

    • Squig ==> “Expected life expectancy” is an Epidemiologists Fantasy League thing….entirely imaginary based on odd assumptions and vague correlations, further damaged by the application of statistics. It is not real science.

  16. …residence would live 1/2 year longer

    As opposed to dying at 91….now you’ll die at 90 and a 1/2

  17. “because they believe the CO2 and other pollution from burning wood is somehow “safer” than fossil fuels”

    It is not “somehow” safer but is really really safer in terms of the theory of AGW which makes a distinction between the current account of the carbon cycle and “external carbon” from deep under the ground injected into the current carbon cycle. In AGW the villain is external carbon from under the ground the injection of which is expected to destabilize the climate system. Trees are current carbon. Gasoline is external carbon. The switch to wood is consistent with the AGW model of climate change.

    I agree that the distinction is nonsensical.
    https://ssrn.com/abstract=2997420
    https://dx.doi.org/10.2139/ssrn.2873672

    • I am so old that I remember SF being a great place to visit.

      SF has become a magnet for those with self destruction disorder.
      work
      Cohen did some interesting and useful work on workplace safety. The most dangerous occupation is being unemployed. Think about that!

  18. ….. I recommend that anyone, who would like to prolong his life
    by 0.3 to 0.6 years (how many months longer life?) to move South
    into Texas…..
    I travelled extensively in India back in the 1970´… I remember,
    around Calcutta, the cow dung patties drying at every wall in the Sun
    …..and the people took 3 of them down, stacked the three and lit them,
    put two stones, left and right, and put their rice dish over it to cook….
    everywhere, all around,.right on the street sidewalks….
    and in the afternoon at 4, the Sun was almost invisible…..
    This knocks off 3 years of life, but it was a very good biofuel, not
    toxic chemically, a pure natural cow product….. somebody needs a
    good GREEN clean bio-business idea?

  19. The folks who do Harvard studies are long on agenda and short on common sense.

    It is bitter cold and the retired guy down the street has a heart attack shoveling snow.

    We are camping and there is a heat advisory. I decide to take my wife to a hotel with AC because of her heart condition. We made it as far as the ER. That was more than 10 years. She survived a lot longer than her father because of modern medicine.

    This summer we were again camping. Air quality was getting bad. I checked AIRNOW and there was no place to go because of the wildfires in California, Washington and Oregon. We headed to a campsite with electricity. It was ugly outside but AC does a good job of removing particulate.

    The question that agenda driven studies do not ask is what are people doing when they die.

    If you die heating your house with wood because you think nuclear power is dangerous, you are an idiot. If you die riding your bike to improve your health, you are an idiot.

    I enjoy burning wood and riding a bike. I gave my bike up when we retired to living in a motorhome. Getting dizzy and falling off could result in my premature death that idiots at Harvard would attribute to pollution in China.

  20. I’ve noticed everyone dies after an average of 75 or so years anyway. Maybe we should work on that more.

    • You need to be very careful with epidemiology studies. There are thousands of studies to establish a link between a certain pollution and mortality. Basically none of those studies measures the exact exposure of the people to the pollution. The exposure is only estimated by measuring the pollution in a measuring station and calculating the concentration at the address of the people in the study. This is the first huge uncertainty.

      The second even bigger uncertainty comes from the assumption that the people are always exposed to that virtual concentration at their front door, which is not the case since people usually dont work and sleep in front of their front door.

      The third uncertainty comes from various computer model adjustments for social conditions of the people, also not measured but assumed depending on location or education.

      The fourth comes from various different statistical models to choose for calculating concentrations and adjustment.

      At the end of the day you can establish a link between any gas (even oxygen) and mortality by choosing and tuning statistical models.

      See William Briggs’ comments on particulate matter: http://wmbriggs.com/post/4353/

      I checked for NO2 since this was a big issue in Germany for the past 2 years. The same thing. Even worse! After reading many of those reports it is quite obvious that no conclusion can be drawn from them. Neither a correlation nor a causation. Most of the studies even miss a valid confounder assessment. When it comes to lung function or mortality CO has also a big impact. With the exception of a very few that was not measured or considered at all!

  21. One might think that US EPA, being so worried about our health and air quality, would have air quality monitoring stations all over. Yet many states have very few, sometimes only one. Often those are located near a known source of pollutions. Often the stations are not operating a good deal of the time. In Florida in the mid-1990s there was one AQ monitoring station. It was in Pensacola. There are now stations listed for more populous areas of the state, e.g., Orlando, Miami, etc but no longer one listed in Pensacola. Fireplaces are common in the north half of the state, often used by people with no understanding how a fireplace should operate properly. The worst AQ problems in at least the northern part of the state is pollen. Tallahassee is not only the capitol of Florida but the allergy capitol of the USA, being affected by not only what grows locally but what is brought in by cold fronts.

  22. In past administrations, the EPA justified regulating all air “pollutants” based on one criteria: if one can hypothesize a small possibility of an environmental threat, measures to respond to the perceived threat are justified. Compelling scientific evidence of a threat of serious damage became a moot point. I call this the one percent solution. The same thinking was advocated by Cheney, and that got the U.S. into the first Iraq war. This mentality in the EPA has to change. More science will likely change nothing regarding policies. The train has left the station.

  23. “I should note that if one smothers due to extraordinary levels of CO2, it is the lack of sufficient oxygen that kills the person, not any CO2 toxic effects.”

    Don’t think so. 6% co2 causes mental confusion, that’s with o2 present. (Diving problem)

  24. For a number of years my wife and I have been supporting a charity which supplies farming materials, animals and teaching on how to use them. One thing they show people how to make is a fuel efficient stove which uses less fuel and also has a flue which removes the harmful fumes from inside the house.
    https://sendacowgifts.org/super-stove

    James Bull

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