Plumes of harmful air pollutants can be transported across oceans and continents — from Asia to the United States and from the United States to Europe — and have a negative impact on air quality far from their original sources, says a new report by the National Research Council.  Although degraded air quality is nearly always dominated by local emissions, the influence of non-domestic pollution sources may grow as emissions from developing countries increase and become relatively more important as a result of tightening environmental protection standards in industrialized countries.  

“Air pollution does not recognize national borders; the atmosphere connects distant regions of our planet,” said Charles Kolb, chair of the committee that wrote the report and president and chief executive officer of Aerodyne Research Inc.  “Emissions within any one country can affect human and ecosystem health in countries far downwind.  While it is difficult to quantify these influences, in some cases the impacts are significant from regulatory and public health perspectives.” 

The report examines four types of air pollutants: ozone; particulate matter such as dust, sulfates, or soot; mercury; and persistent organic pollutants such as DDT.  The committee found evidence, including satellite observations, that these four types of pollutants can be transported aloft across the Northern Hemisphere, delivering significant concentrations to downwind continents.  Ultimately, most pollutants’ impacts depend on how they filter down to the surface.  

Current limitations in modeling and observational capabilities make it difficult to determine how global sources of pollution affect air quality and ecosystems in downwind locations and distinguish the domestic and foreign components of observed pollutants.  Yet, some pollutant plumes observed in the U.S. can be attributed unambiguously to sources in Asia based on meteorological and chemical analyses, the committee said.  For example, one study found that a polluted airmass detected at Mt. Bachelor Observatory in central Oregon took approximately eight days to travel from East Asia.  

The health impacts of long-range transport vary by pollutant.  For ozone and particulate matter — which cause respiratory problems and other health effects — the main concern is direct inhalation.  While the amount of ozone and particulate matter transported on international scales is generally quite small compared with domestic sources, neither of these pollutants has a known “threshold,” or concentration below which exposure poses no risk for health impacts.  Therefore, even small incremental increases in atmospheric concentrations can have negative impacts, the committee said.  For instance, modeling studies have estimated that about 500 premature cardiopulmonary deaths could be avoided annually in North America by reducing ozone precursor emissions by 20 percent in the other major industrial regions of the Northern Hemisphere. 

For mercury and persistent organic pollutants, the main health concern is that their transport and deposition leads to gradual accumulation on land and in watersheds, creating an increase in human exposure via the food chain.  For example, people may consume mercury by eating fish.  There is also concern about eventual re-release of “legacy” emissions that have been stored in soils, forests, snowpacks, and other environmental reservoirs. 

In addition, the committee said that projected climate change will lead to a warmer climate and shifts in atmospheric circulation, likely affecting the patterns of emission, transport, transformation, and deposition for all types of pollution.  However, predicting the net impacts of the potential changes is extremely difficult with present knowledge. 

In the coming decades, man-made emissions are expected to rise in East Asia, the report says.  These increases could potentially be mitigated by increasingly stringent pollution control efforts and international cooperation in developing and deploying pollution control technology. 

To enhance understanding of long-range transport of pollution and its impacts, the committee recommended a variety of research initiatives, such as advancing “fingerprinting” techniques to better identify source-specific pollutant characteristics, and examining how emissions from ships and aircraft affect atmospheric composition and complicate the detection of pollution from land-based sources.  The committee emphasized developing an integrated “pollution source-attribution” system that improves capabilities in emissions measurements and estimates; atmospheric chemical and meteorological modeling; long-term, ground-based observations; satellite remote sensing; and process-focused field studies.  

Moreover, the committee stressed that the United States, as both a source and receptor of long-range pollution, has an interest in remaining actively engaged in air pollutants that travel abroad, including support of more extensive international cooperation in research, assessment, and emissions control efforts. 

The report was sponsored by the U.S. Environmental Protection Agency, National Oceanic and Atmospheric Administration, NASA, and National Science Foundation.  The National Academy of Sciences, National Academy of Engineering, Institute of Medicine, and National Research Council make up the National Academies.  They are independent, nonprofit institutions that provide science, technology, and health policy advice under an 1863 congressional charter.  Committee members, who serve pro bono as volunteers, are chosen by the Academies for each study based on their expertise and experience and must satisfy the Academies’ conflict-of-interest standards.  The resulting consensus reports undergo external peer review before completion.  For more information, visit National Academies  A committee roster follows. 

Reference: National Academy of Sciences, Air Pollutants From Abroad a Growing Concern, Says New Report, Washington, September 29. 2009

Studies show chemicals act as toxicants in causing cases of Multiple Chemical Sensitivity; genes that metabolize these chemicals into other forms influence, therefore, susceptibility to getting MCS.

Guest post at Canary Report by Martin L. Pall, Professor Emeritus of Biochemistry and Basic Medical Sciences, Washington State University and Research Director, the Tenth Paradigm Research Group.

Martin Pall: I have emailed the following as an open letter to the Denver Post in response to the article on multiple chemical sensitivity (MCS) that was published this weekend. I think the published article was generally a step forward in terms of public understanding of MCS. But the article left out a number of important things and this letter is an attempt to deal with some of those. I have asked them to consider publishing this as an Op-Ed piece, but wanted to make it available regardless of whether or not they opt to do so.

Thank you for writing this article on multiple chemical sensitivity (MCS), the term that is used in most of the scientific literature on this disease. There are vast numbers of people who have been afflicted in this epidemic of chemical sensitivity and I am sure that they are all thanking you. I also thank you for mentioning a bit of my work on this disease.

Some of your readers have already made quite a number of important points about MCS so I can focus here on just a few remaining issues. How do chemicals act in MCS? We know now that the seven classes of chemicals implicated in MCS all produce a common toxic response in the body, excessive activity of a receptor in the body called the NMDA receptor. So even though we have a vast array of such chemicals, we know how they can produce similar responses in people.

There is compelling genetic evidence that these chemicals act as toxic agents (toxicants) in the body. Four such studies have been published by three research groups in three countries. Collectively they implicate six genes as influencing susceptibility to MCS, such that people carrying some forms of each of these genes are more susceptible to becoming chemically sensitive than are people carrying other forms of the same genes. All of these genes control the activity of enzymes that metabolize these chemicals into other forms. Most of these studies show a high level of what is called statistical significance. In the Schnakenberg and colleagues studies, the chances of getting their results by chance are less than one in a million billion. So obviously, these are not chance results. What these studies show is that chemicals are acting as toxicants in causing cases of MCS and that genes that metabolize these chemicals into other forms influence, therefore, susceptibility to getting MCS. These studies, then, provide compelling evidence that cases of MCS are caused by toxic chemical exposure. Clearly they also show that MCS is a real disease, otherwise one would not be able to do such studies clearly linking the chance of becoming ill with MCS to the action of chemicals acting as toxicants.

Dr. Herman Staudenmayer has, for some 20 years claimed just the opposite. He claims that MCS is psychogenic, caused by psychological responses and according to him, is not a toxicological phenomenon. He has maintained this claim by ignoring contrary data wherever it occurs. He has ignored all of the evidence that chemicals implicated in MCS produce a common response in the body; he has ignored the roughly two dozen studies showing that MCS patients show objectively measurable responses to low level chemical exposures, responses that differ from those of normals. He has ignored all of the evidence implicating excessive NMDA activity in MCS; he has ignored the dozens of animal model studies on MCS; he has ignored over 50 studies that show that cases of MCS typically occur following chemical exposures; he has ignored the various other measurable physiological changes reported to occur in MCS. This has all been documented in my book “Explaining – Unexplained Illnesses” and in my article on the toxicology of MCS that is coming out next month in a prestigious reference work for professional toxicologists “General and Applied Toxicology, 3rd Edition”. It is also documented on the MCS web page of my web site: The Tenth Paradigm

Clearly you cannot do science by simply ignoring the existence of vast arrays of contrary data. However, Staudenmayer provides us with a couple of other tests of his views in his book, predictions that allow us to test his theory. He predicts that psychological factors are necessary and sufficient to account for the properties of MCS. This, of course, is contradicted by all of the evidence I referred to earlier. Therefore we should reject his hypothesis based on his own prediction. He provides a second prediction as well (the exact quotes from his book on these predictions are provided on my MCS web page). He predicts that the variation of susceptibility to MCS is not caused by variable responses to toxic chemicals. Clearly the genetic studies discussed above have shown that this is false and therefore, his hypothesis should be rejected for that reason, as well.

It is clear, from the above, that Staudenmayer’s construct was basically a house of cards. Now that it has collapsed, where does that leave us?

Firstly it leaves us with reversing the errors of the past. We need to start treating MCS sufferers as victims of unsafe chemical exposure. Many of them have previously been used, abused and discarded. If we live in a society where people are not disposable items we need to “do unto others as you would have others do unto you.”

We obviously need to start regulating chemical usage much more carefully, to avoid initiating new cases of MCS. It is imperative to develop tests for chemical activity in MCS, just as we have developed tests for chemical activity as carcinogens. Then we need to use these tests to effectively regulate the use of toxic chemicals.

We need to develop specific biomarker tests for MCS, tests that can be used to objectively confirm diagnoses initially based on subjective symptoms. I think we already have several very promising approaches to doing this in the scientific literature and a minimal amount of further study may be all that is needed to develop such tests.

We need to confirm that chemical avoidance is key to therapy and to develop other therapeutic approaches to work along with avoidance. The environmental medicine physicians and others have already made very important progress in this direction and I am optimistic that further progress can be made quickly. Such progress is relevant not only to the treatment of MCS patients but also to the treatment of clearly related diseases including chronic fatigue syndrome/mylagic encephalomyelitis and fibromyalgia. All of these diseases are caused by what I have called the NO/ONOO- cycle and the way to treat them, in my judgment, is to lower the activity of that vicious cycle mechanism.

Martin L. Pall

Professor Emeritus of Biochemistry and Basic Medical Sciences, Washington State University and Research Director, the Tenth Paradigm Research Group

Reprinted with permission from the author. Dr. Pall cautions the reader that he is a PhD, not an MD, and none of this should be viewed as medical advice.

• Original Article posted by Canary Report Thank you for the permission to reprint Susie!
• Link to Martin Pall’s website: The Tenth Paradigm
• Link to an extended excerpt from Palls book Explaining “Unexplained Illnesses.”

Growing evidence shows that exposure to lead in the environment is associated with cardiovascular disease, including increased risk of hypertension. However, those studies have looked at lead concentrations in blood, not bone lead, a better indicator of cumulative lead exposure over time. In a new study, researchers at the Harvard School of Public Health (HSPH) and the University of Michigan School of Public Health found that bone lead was associated with a higher risk of death from all causes, particularly from cardiovascular disease. It is the first study to analyze the association between bone lead and mortality.

The study appears online on September 8, 2009, on the website of the journal Circulation and will appear in a later print edition. 

“The findings with bone lead are dramatic. It is the first time we have had a biomarker of cumulative exposure to lead and the strong findings suggest that, even in an era when current exposures are low, past exposures to lead represent an important predictor of cardiovascular death, with important public health implications worldwide,” said Marc Weisskopf, assistant professor of environmental and occupational epidemiology at HSPH and lead author of the study.

Air pollution was the main source of lead in the environment in recent years, though it has been decreasing since leaded gasoline was banned in the U.S. in the mid-1990s. Most of the lead circulating in the body is deposited in bone and remains there for years, unlike blood lead, which has a half life of about 30 days. Since adverse effects from lead on the cardiovascular system would be expected to show up over time, the researchers expected that bone lead would be a better marker of chronic toxicity.

The researchers, led by Weisskopf and senior author Howard Hu, professor of environmental health, epidemiology and internal medicine at the University of Michigan School of Public Health, analyzed data from 868 participants in the Department of Veterans Affairs Normative Aging Study, a study of aging in men that began in 1963. Blood lead and bone lead—analyzed using X-ray fluorescence—were measured for each of the participants. The results showed that the risk of death from cardiovascular disease was almost six times higher in men with the highest levels of bone lead compared to men with the lowest levels. The risk of death from all causes was 2.5 times higher in men with the highest levels of lead compared to those with the lowest levels. The results appeared independent of age, smoking, education, race, alcohol, physical activity, BMI, high density lipoprotein or total cholesterol levels, hypertension or diabetes.

There are a number of mechanisms, such as increased oxidative stress, by which lead exposure may result in cardiovascular mortality, say the authors. They also note that, in addition to high blood pressure, exposure to lead has been associated with widened pulse-pressure (an indicator of arterial stiffening) and heart disease.

Given that bone lead may be a better biomarker of cumulative lead exposure than blood lead, it may be the best predictor of chronic disease from exposure to lead in the environment. “In addition to spurring further public health measures to reduce exposure to lead and to begin monitoring for cumulative exposure, mechanistic and clinical research is needed to determine if opportunities exist to conduct targeted screening and treatment that can further reduce the burden of cardiovascular disease for the millions of adults who have had years of elevated lead exposure in the past,” said Hu.

Reference:    Harvard School of Public Health, Lead in bone associated with increased risk of death from cardiovascular disease in men, Boston, MA, September 9, 2009