Long-lived, upper trophic level marine mammals are vulnerable to bioaccumulation of persistent organic pollutants (POPs). Internal tissues may accumulate and mobilize POP compounds at different rates related to the body condition of the animal and the chemical characteristics of individual POP compounds; however, collection of samples from multiple tissues is a major challenge to ecotoxicology studies of free-ranging marine mammals and the ability to predict POP concentrations in one tissue from another tissue remains rare. Northern elephant seals (Mirounga angustirostris) forage on mesopelagic fish and squid for months at a time in the northeastern Pacific Ocean, interspersed with two periods of fasting on land, which results in dramatic seasonal fluctuations in body condition. Using northern elephant seals, we examined commonly studied tissues in mammalian toxicology to describe relationships and determine predictive equations among tissues for a suite of POP compounds, including ΣDDTs, ΣPCBs, Σchlordanes, and ΣPBDEs. We collected paired blubber (inner and outer) and blood serum samples from adult female and male seals in 2012 and 2013 at Año Nuevo State Reserve (California, USA). For females (N = 24), we sampled the same seals before (late in molting fast) and after (early in breeding fast) their approximately seven month foraging trip. For males, we sampled different seals before (N = 14) and after (N = 15) their approximately four month foraging trip. We observed strong relationships among tissues for many, but not all compounds. Serum POP concentrations were strong predictors of inner blubber POP concentrations for both females and males, while serum was a more consistent predictor of outer blubber for males than females. The ability to estimate POP blubber concentrations from serum, or vice versa, has the potential to enhance toxicological assessment and physiological modeling. Furthermore, predictive equations may illuminate commonalities or distinctions in bioaccumulation across marine mammal species.

Air pollution is recognized as an important risk factor for cardiovascular disease. We investigated association of exposure to occupational air pollution and cardiac function in the workers of the steel industry. Fifty male workers of the agglomeration and coke-making parts of the Esfahan Steel Company were randomly selected (n = 50). Workers in the administrative parts were studied as controls (n = 50). Those with known history of hypertension, dyslipidemia, or diabetes, and active smokers were not included. Data of age, body mass index, employment duration, blood pressure, fasting blood sugar, and lipid profile were gathered. Echocardiography was performed to evaluate cardiac function. Left ventricular ejection fraction was lower in workers of the agglomeration/coke-making parts than in controls (mean difference = 5 to 5.5 %, P < 0.001). Mild right ventricular dilatation and grade I pulmonary hypertension were present in three (12 %) workers of the coke-making part, but none of the controls (P = 0.010). According to these results, occupational air pollution exposure in workers of the steel industry is associated with left heart systolic dysfunction. Possible right heart insults due to air pollution exposure warrant further investigations.

The aim of this study is to evaluate blood cadmium levels (BCLs) in Chinese adults and explore whether blood cadmium is associated with diabetes or obesity. This study included 5544 adults from a cross-sectional SPECT-China study. BCL and blood lead level (BLL) was measured by atomic absorption spectrometry. Fasting plasma glucose (FPG) was used to define prediabetes and diabetes. Overweight and obesity were defined by body mass index (BMI). The associations of BCL with prediabetes, diabetes, overweight, and obesity were analyzed by multinomial logistic regression analyses. Medians (interquartile range) of BCL were 1.97 μg/L (0.60–3.82) in men and 1.59 μg/L (0.54–3.51) in women. Subjects in low-economic-status areas and urban areas had significantly higher BCL. BCL in current smokers was significantly higher than in current non-smokers. In the adjusted model, a mild positive relationship between BCL and FPG was found. Meanwhile, the prevalence of prediabetes was increased according to the increase in BCL tertiles. Surprisingly, BCL had a negative relationship with prevalence of overweight. In conclusion, BCL in Chinese adults was much higher than in other developed countries and was influenced by gender, smoking, and residential area. BCL was positively related to prediabetes while negatively related to overweight.