MERCURY, ARSENIC AND SELENIUM IN CHANNEL CATFISH CAUGHT IN SOUTHWESTERN PENNSYLVANIA; IMPLICATIONS FOR COAL-FIRED POWER PLANT EMISSION SOURCE IDENTIFICATION AND FISH CONSUMPTION SAFETY

摘要

This study recruited local anglers to catch catfish from 3 locations within the Pittsburgh Pool and an upstream location on Allegheny River at Kittanning Dam to compare the As, Hg and Se levels in catfish fillet. The objectives were: to find if there exist locational differences of As, Hg and Se levels in catfish flesh; use catfish as sentinels to identify the sources of pollution; determine if any catfish had mercury levels above the EPA criterion; and assess the consumption risk for semi-subsistence anglers and their families. Local store-bought catfish are also compared with river-caught samples.Fish tissue was prepared following EPA method 3052. As and Se were analyzed by collision cell ICP-MS with calibration by standard addition methods. Mercury was analyzed by isotope dilution cold vapor ICP-MS. Data were log-transformed and analyzed by ANOVA with Tukey Post-Hoc Comparisons.There were no significant differences in As, Hg and Se concentrations among the Pittsburgh Pool catch, so we combined these data. Significantly higher levels of Hg and Se were found in Kittanning-caught fish even given significantly smaller fish sizes compared to those caught in the Pittsburgh Pool. The store-bought fish were significantly lower in As, Hg and Se than those caught in the Pittsburgh Pool. In addition, 23% of samples caught in Kittanning had higher mercury levels than the EPA criterion. Hg and Se levels in samples are significantly positively correlated. Using upper 95% CI of mean mercury level in Kittanning-caught catfish flesh, the maximum monthly allowable fish consumption limit for adult anglers is 4 meals, for children below 16 years old is 2 meals, and for women of childbearing age is 3 meals. Conclusions: The Hg and Se levels in catfish in Pittsburgh Rivers vary significantly by location. Fishers are exposed to higher Hg and Se levels when they eat the fish caught near Kittanning and Pittsburgh pool than bought from the fish market. Public health implications: River areas upstream from Pittsburgh may have higher mercury levels than those nearer Pittsburgh because of deposition of emissions from coal-fired power plants. Location specific fish consumption advisories are needed for local fishers.