Documents Miller, Anthony B. 2 results

"Objectives: To evaluate the risk of having a child with a congenital anomaly in relation to occupational exposure to low level ionising radiation in the pre-conception period.

Methods: A case-control study based on the Canadian congenital anomalies registry used record linkage techniques to identify congenital anomalies among male and female workers in Canada's largest electric company. Cases were defined as parents of a child with a congenital anomaly born between April 1979 and December 1986 who had a congenital anomaly diagnosed within the first year of life. Controls were an individually matched sample of parents of a liveborn child without an anomaly. Risk of congenital anomaly was assessed in relation to parental exposure to ionising radiation acquired through work within a nuclear generating station of an electric power company. Exposure was assessed according to employment, whether or not the worker was monitored for radiation exposure, and quantitative estimates of radiation dose.

Results: Employment within the electric power industry was not associated with an increased risk of congenital anomalies in the offspring of mothers or fathers. Risk estimates for workers monitored (those who are likely to be exposed to ionising radiation) were 1.75 (95% confidence interval (95% CI) 0.86 to 3.55) for mothers and 0.84 (95% CI 0.68 to 1.05) for fathers. Exposure for fathers before conception, defined cumulatively and for six months before conception, was not associated with increased risk of anomalies in their offspring. There were no significant increases in risk found between type of anomaly and any measure of exposure, although the statistical power in these groups was limited. The study had insufficient numbers to evaluate the effects of ionising radiation in mothers as only three mothers had recorded doses > 0 mSv.

Conclusions: Overall, workers in a nuclear power industry, and specifically those exposed before conception to low levels of ionising radiation, do not appear to be at an increased risk of having a liveborn child with a congenital anomaly."

"Occupational exposure to strong-inorganic-acid mists containing sulfuric acid has been recognized as a Group 1 carcinogen since 1992. The greatest effects have been observed for laryngeal cancer, with fewer studies implicating lung cancer. An augmented, secondary data analysis of a population-based case-control study of lung cancer was conducted to assess lung cancer-specific risks. The data set was derived from a previous study of 772 lung-cancer cases, including all new female lung cancer cases diagnosed between 1981 and 1985, and one age- and hospital-matched male lung cancer case per female case during the same period. Individually-matched controls – on age, gender, and borough of residence – were identified. Lifetime exposure to 10 acidic agents including strong inorganic acids and some gases was assessed by experienced occupational hygienists from complete lifetime occupational histories in terms of concentration, frequency and reliability of the various exposure assessments. Smoking-adjusted (log (1 + pack-years/5)) odds ratios and 95% confidence intervals were determined for overall and histology-categorized lung cancers using conditional logistic regression. Effect modification by gender was explored with interaction terms for each exposure. No excess risk for overall lung cancer was associated with any of the acids. No effect modification by gender could be identified. This finding of no lung cancer effect in our study population reinforces more recent toxicological data, which suggests specificity of acid effects to the larynx."