Concentration Trends for Lead and Calcium-Normalized Lead in Fish Fillets from the Big River, a Mining-Contaminated Stream in Southeastern Missouri USA.
Lead (Pb) and calcium (Ca) concentrations were measured in fillet samples of longear sunfish (Lepomis megalotis) and redhorse suckers (Moxostoma spp.) collected in 2005-2012 from the Big River, which drains a historical mining area in southeastern Missouri and where a consumption advisory is in effect due to elevated Pb concentrations in fish. Lead tends to accumulated in Ca-rich tissues such as bone and scale. Concentrations of Pb in fish muscle are typically low, but can become elevated in fillets from Pb-contaminated sites depending in part on how much bone, scale, and skin is included in the sample. We used analysis-of-covariance to normalize Pb concentration to the geometric mean Ca concentration (415 ug/g wet weight, ww), which reduced variation between taxa, sites, and years, as was the number of samples that exceeded Missouri consumption advisory threshold (300 ng/g ww). Concentrations of Pb in 2005-2012 were lower than in the past, especially after Ca-normalization, but the consumption advisory is still warranted because concentrations were >300 ng/g ww in samples of both taxa from contaminated sites. For monitoring purposes, a simple linear regression model is proposed for estimating Ca-normalized Pb concentrations in fillets from Pb:Ca molar ratios as a way of reducing the effects of differing preparation methods on fillet Pb variation.
Columbia Environmental Research Center, U.S. Geological Survey, 4200 New Haven Rd., Columbia, MO, 65201, USA. cjschmitt@usgs.gov.
Christopher J
http://orcid.org/0000-0001-6804-2360
CJ
Schmitt
Central Regional Office and Conservation Research Center, Missouri Department of Conservation, 3500 E. Gans Rd., Columbia, MO, 65201, USA.
Michael J
MJ
McKee
D000818:Animals; D002118:Calcium / Q000032:analysis*; D003531:Cypriniformes / Q000378:metabolism; D004784:Environmental Monitoring; D005396:Fish Products / Q000032:analysis; D005399:Fishes / Q000378:metabolism*; D007854:Lead / Q000032:analysis*; D008906:Mining; D008923:Missouri; D010473:Perciformes / Q000378:metabolism; D045483:Rivers / Q000737:chemistry*; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000032:analysis
D014874:Water Pollutants, Chemical; D007854:Lead; D002118:Calcium
Calcium; Lead; Longear sunfish; Mining; Redhorse suckers