Effect of early life exposure to air pollution on development of childhood asthma.

BACKGROUND: There is increasing recognition of the importance of early environmental exposures in the development of childhood asthma. Outdoor air pollution is a recognized asthma trigger, but it is unclear whether exposure influences incident disease. We investigated the effect of exposure to ambient air pollution in utero and during the first year of life on risk of subsequent asthma diagnosis in a population-based nested case-control study. METHODS: We assessed all children born in southwestern British Columbia in 1999 and 2000 (n = 37,401) for incidence of asthma diagnosis up to 34 years of age using outpatient and hospitalization records. Asthma cases were age- and sex-matched to five randomly chosen controls from the eligible cohort. We estimated each individual's exposure to ambient air pollution for the gestational period and first year of life using high-resolution pollution surfaces derived from regulatory monitoring data as well as land use regression models adjusted for temporal variation. We used logistic regression analyses to estimate effects of carbon monoxide, nitric oxide, nitrogen dioxide, particulate matter

Uptake of cadmium from Pacific oysters (Crassostrea gigas) in British Columbia oyster growers.

BACKGROUND: Pacific oysters along the North American coast from Washington to Alaska contain concentrations of cadmium (Cd) that are high by comparison with Atlantic oysters, frequently exceeding 2mug/g wet weight, but it is unclear whether this Cd is absorbed by consumers. OBJECTIVES: To determine the effect of oyster consumption on Cd in blood and urine among a group with high oyster consumption. METHODS: Sixty-one non-smoking oyster growers and family members with a mean age of 47.3+/-7.6 years (range 33-64) were interviewed by telephone to assess their oyster consumption and other sources of Cd exposure at present and 5 years prior to the start of oyster farming. Their blood and urine Cd concentrations were measured. RESULTS: The geometric mean Cd concentration in blood was 0.83mug/L and in urine was 0.76mug/g creatinine. Thirty-six percent of participants had urinary Cd levels above 1mug/g creatinine and 5% were above 2mug/g creatinine. Recent (last 12 months) and long-term oyster consumptions were positive predictors of blood Cd but did not directly predict urinary Cd. The optimal model for predicting the variance in blood Cd included recent intake of oyster-derived Cd, serum iron concentration and recent ketchup consumption (R(2)=0.34, p=0.00004), with the latter two variables showing a protective effect. The factors found to predict urinary Cd were blood Cd concentration and duration of oyster farming. A rise in blood Cd was observed after 12 years of farming oysters, likely caused by higher consumption of oysters during this period. CONCLUSIONS: Oyster-derived Cd is bioavailable and affects body stores of the metal.