BACKGROUND: Methylmercury is an organic form of mercury that is highly toxic to humans. Here, we present and establish a novel method to detect methylmercury concentrations in the blood of Koreans. METHODS: Methylmercury concentration was analyzed with an automated methylmercury analytic system (MERX, Brooks Rand Co., USA) using cold vapor atomic fluorescence spectrophotometry (CVAFS). A variety of biological materials were digested in methanolic potassium hydroxide solution. The analysis method was validated by examination of certified reference material (955c, National Institute of Standard and Technology, USA). We randomly selected 30 Korean adults (age 20 yr or older) to analyze total blood mercury and methylmercury concentrations. RESULTS: The detection limit and methylmercury recovery rate using this method were 0.1 pg/L and, 99.19% (range: 89.33-104.89%), respectively. The mean blood concentration of methylmercury was 4.54+/-2.15 microg/L (N=30). The mean proportion of methylmercury to the total mercury concentration was 78.27% (range: 41.37-98.80%). CONCLUSIONS: This study is the first report to analyze blood methylmercury concentration using CVAFS in Korea. We expect that this method will contribute to the evaluation of mercury exposure and the assessment of the toxicological impact of mercury in future studies.
Adult ; Humans ; Hydroxides/chemistry ; Mercury/blood ; Methylmercury Compounds/*blood ; Potassium Compounds/chemistry ; Reproducibility of Results ; Republic of Korea ; *Spectrophotometry, Atomic

OBJECTIVETo study the oxidative stress induced by consumption of mercury-contaminated rice in rats, and to assess the possible public health risk of mercury contamination in Wanshan mining area.

METHODSSprague Dawley rats were fed the mercury-contaminated rice produced from Wanshan area for 90 days. The antioxidant status and the free radicals in rat serum were evaluated.

RESULTSHigh mercury accumulation in organs of rats fed the mercury-contaminated rice confirmed the server pollution of mercury in Wanshan mining area. The intensity of electron spin resonance (ESR) signal increased by 87.38% in rats fed the rice from Wanshan compared with that in the control rats fed the rice from Shanghai, suggesting that chronic dietary consumption of rice from mercury mining area could induce an aggravation of free radicals. Feeding the mercury-contaminated rice was associated with significant decreases in the antioxidant enzymatic activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and concentration of serum nitric oxide (NO), but it had no effect on serum nitric oxide synthase (NOS) activity. Feeding the mercury-contaminated rice raised the level of serum malonyldialdehyde (MDA), indicating the occurrence of oxidative stress.

CONCLUSIONThe long-term dietary consumption of mercury-contaminated rice induces the aggravation of free radicals and exerts oxidative stress.

Animals ; Brain ; metabolism ; China ; Environmental Pollutants ; analysis ; pharmacokinetics ; toxicity ; Food Contamination ; analysis ; Free Radicals ; blood ; Glutathione Peroxidase ; blood ; Industrial Waste ; adverse effects ; Kidney ; metabolism ; Liver ; metabolism ; Malondialdehyde ; blood ; Mercury ; analysis ; pharmacokinetics ; toxicity ; Methylmercury Compounds ; analysis ; pharmacokinetics ; toxicity ; Nitric Oxide ; blood ; Nitric Oxide Synthase ; blood ; Oryza ; Oxidative Stress ; Rats ; Rats, Sprague-Dawley ; Superoxide Dismutase ; blood