Polycyclic aromatic hydrocarbons

Polycyclic aromatic hydrocarbons (PAH) are a group of structurally related chemical compounds that are frequently produced during incomplete combustion of organic matter and are among the most widespread environmental pollutants. This chapter enumerates common sources of environmental PAH that contribute to human exposures including air and water pollution, residential soil and marine sediments, occupational exposures, and lifestyle sources such as cigarette smoking and diet. It summarizes toxic effects in humans, particularly carcinogenesis, along with recent developments in measurable biomarkers of exposure

A Case Study of Tire Crumb Use on Playgrounds: Risk Analysis and Communication When Major Clinical Knowledge Gaps Exist

Physicians and public health professionals working with the U.S. Environmental Protection Agency’s Region 8 Pediatric Environmental Health Specialty Unit (PEHSU) received several telephone calls requesting information regarding the safety of recycled tire crumb as a playground surface constituent placed below children’s play structures. There were no reported symptoms or adverse health effects in exposed children. The literature available on the safety and risk of exposure to crumb rubber constituents was limited and revealed no information quantifying exposures associated with product use. Callers were informed by the PEHSU that no evidence existed suggesting harm from intended use of the product, but gaps in knowledge about the product were identified and communicated. Here the case of crumb rubber on playgrounds is used as a model to present an approach to similar environmental medicine questions. From defining the question, to surveying traditional and nontraditional resources for information, synthesis of findings, and risk communication, the case provides a model to approach similar questions

Trends in Mortality from Chronic Obstructive Pulmonary Disease in Alberta: Back to the Future?

Trends in mortality from chronic obstructive pulmonary disease (COPD) in Alberta over 60 years, from 1927 to 1987, for ages 15 and above or both sexes, were examined. There was a striking decline in mortality among older adults in the 1930s and 1940s. a nadir that lasted almost 10 years in the 1950s, and a striking increase thereafter. By 1970, most age groups had returned to levels of the 1930s. This overall trend was observed in both the younger age groups (aged 15 to 50) and older adults, although mortality from COPD in the former disproportionately reflected asthma-related deaths. Subsequently, mortality climbed still higher in older age groups, but not in the younger age groups. The sustained rise in mortality in older age groups after the Second World War is presumably related to smoking habits. Historical trends in Alberta were then compared with Canada as a whole for both sexes over 50 years of age. Although Alberta had a much lower mortality from COPD than Canada as a whole, this difference disappeared by 1980. There is no obvious explanation that would explain all of the observed trends, but they appear more likely to be a consequence of social and environmental conditions, including changes in health-related behaviour, than of major changes in medical management at the time