Inorganic arsenic in drinking water and bladder cancer: a meta-analysis for dose-response assessment.
Most arsenic cancer risk assessments have been based solely on epidemiological studies to characterize the dose-response relationship for arsenic-associated cancer and to perform risk calculations. However, current epidemiological evidence is too inconsistent and fraught with uncertainty regarding arsenic exposure to provide reliable estimates. This makes it hard to draw a firm conclusion about the shape and slope of the dose-response relationship from individual studies. Meta-analysis is a statistical approach to combining results across studies and offers expanded opportunities for obtaining an improved dose-response relationship. In this study, a meta-analysis of arsenic studies was conducted by combining seven epidemiological studies from different regions to get an overall dose-response relationship between the amount of arsenic intake and the excess probability of bladder cancer. Both the fixed-effect and random-effect models were used to calculate the averaged coefficient of the linear-logistic regression model. A homogeneity test was also conducted. The final product of this research is an aggregated dose-response model in the range of empirical observation of arsenic. Considering the most recent arsenic MCL (maximum contaminant level, i.e. 10microg/L), the associated bladder cancer risk (lifetime excess probability) at this MCL is 2.29 x 10-5.
Chu
Huei-An
HA
Department of Environmental Sciences and Engineering, School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
Crawford-Brown
Douglas J
DJ
D001151:Arsenic / Q000032:analysis*; D020261:Arsenic Poisoning / Q000150:complications* / Q000453:epidemiology*; D016022:Case-Control Studies; D015331:Cohort Studies; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008962:Models, Theoretical; D012306:Risk; D001749:Urinary Bladder Neoplasms / Q000139:chemically induced* / Q000453:epidemiology / Q000209:etiology; D014874:Water Pollutants, Chemical; D014881:Water Supply / Q000032:analysis*
D014874:Water Pollutants, Chemical; D001151:Arsenic