secret-science-under-attack-at-the-epa-82814 [wiki.modywzm.pl]

In Part 1 of this two-part series, I detailed how there has been a growing furor over the U.S. Environmental Protection Agency’s (E.P.A.’s) proposed “Strengthening Transparency in Regulatory Science” rule — most often referred to as the Secret Science rule. A majority of the expressed concern about the rule deals with the Harvard Six Cities Study — which is being defended by opposing the proposed E.P.A. This is a perfectly fine preliminary study of the topic. “The adjusted mortality-rate ratio for the most polluted of the cities as compared with the least polluted was 1.26 (95 percent confidence interval, 1.08 to 1.47). Air pollution was positively associated with death from lung cancer and cardiopulmonary disease but not with death from other causes considered together. “Although the effects of other, unmeasured risk factors cannot be excluded with certainty, these results suggest that fine-particulate air pollution, or a more complex pollution mixture associated with fine particulate matter, contributes to excess mortality in certain U.S. The study had, in total, 8,111 subjects , all white — in six different cities — roughly 1300 subjects per city. Of these, there were 1429 deaths over the 14-16 years follow-up or about 230 deaths per city. The city-specific rate ratios are all expressed in relation to Portage, Wisconsin. Only the highlighted categories have Confidence Intervals (CIs) that DO NOT include the NULL (risk ratio of 1 — which indicates no difference in effect found). All of the CIs that don’t include “1” have a range that starts very low. The chart shows clearly that it is chiefly Former and Current Smokers and those with Occupational Exposure (to gases, fumes, or dust) that show even a simple associational effect from fine-particulate air pollution. BMIs that show even small associational effects. The cities are listed in order of least-pollution to highest-pollution. ONLY Steubenville — highlighted in YELLOW — the most polluted city, has a significant result, and that only for men. What does “includes the NULL effect rate ratio of 1” mean? These two cartoon images demonstrate that Rate Ratios that include the rate ratio of 1 are compatible with the NULL hypothesis that there is NO EFFECT. What does that mean for the Six Cities study findings? Very few of the statistical results in the Six Cities Study meet the requirements for being significant and rejecting the null hypothesis of “no effect”. Those that pass this simple basic test have results that are very small and are directly related to other known causes for the posited effect — smoking, occupational exposure, low socio-economic status, and high BMI. When comparing “more polluted cities” to the “least polluted city” ONLY ONE city, the most polluted city — Steubenville, Ohio — shows any significant effect at all. For a short introduction on the topic of evaluating environmental epidemiological results, see this seminal paper: ”The environment and disease: association or causation? ” by Sir Austin Bradford Hill from the Journal of the Royal Society of Medicine. This article has been done by Essay Freelance Writers . Consistency of the observed association: The Six Cities findings are not consistent across cities’ air pollution levels, or between genders. The greatest consistency is with smoking status — current or former — but not with air pollution levels. Temporal relationship of the association - which is the cart and which the horse? The Six Cities study followed the cohort for 14-to-16 years. There is no data in the published study that relates how long the subjects lived in the cities under consideration — so this factor cannot be evaluated. Biological gradient, or dose-response curve: The rate ratios between cities — by pollution levels — do not demonstrate a dose-response curve — effects are not consistently larger as pollution levels increase, effects are not consistent between genders, and only the most polluted city shows a significant effect, and that only for men. It is biologically plausible that air pollution could cause increased mortality.