Search

Inorganic arsenic (iAs) and total arsenic (tAs) were determined in common food from the Swedish market. Special focus was on rice, fish and shellfish products. For the speciation of iAs the European standard EN:16802 based on anion exchange chromatography coupled to ICP-MS was used. The two market basket food groups cereals (including rice), and sweets and condiments (a mixed group of sugar, sweets, tomato ketchup and dressings), contained the highest iAs levels (means 9 and 7 μg iAs/kg), whereas other food groups, including fish, did not exceed 2 μg iAs/kg. Varying levels of iAs were found in separate samples of tomato ketchup, 2.4-26 μg/kg, and is suggested to be one reason of the rather high average level of iAs in the food group sweets and condiments. Some specific food products revealed iAs levels much higher, i.e. rice crackers 152 and Norway lobster 89 μg iAs/kg. The intake of iAs via food was estimated by data from two national consumption surveys, performed in 2010-11 (1797 adults) and 2003 (2259 children). The estimated median iAs intakes in adults and children were 0.047 and 0.095 μg/kg body weight and day, respectively. The iAs intake for rice eaters was about 1.4 times higher than for non-rice eaters. Validation of the consumption survey-based iAs intake, using food purchase and market basket data mainly from 2015, resulted in a per capita intake of a similar magnitude, i.e. 0.056 μg/kg body weight and day. The estimated cancer risk for adults using low-dose linear extrapolation is <1 per 100,000 per year., (Copyright © 2019 Elsevier B.V. All rights reserved.)

We conducted a cross-sectional study in Sweden, Italy and Poland to assess environmental and occupational exposure to mercury from chloralkali (CA) plants and the potential association with biomarkers of early renal dysfunction. Questionnaire data and first-morning urine samples were collected from 757 eligible subjects. Urine samples were analysed for mercury corrected for creatinine (U-HgC), alpha-1-microglobulin (A1M), N-acetyl-beta-glucosaminidase (NAG) and albumin. Determinants of urinary mercury excretion were examined. Levels of kidney markers were compared in three U-HgC categories, and differences were tested taking age and other covariates into account. In the general population, the median U-HgC was higher in Italian (1.2 microg/gC) than in Polish (0.22 microg/gC) or Swedish (0.21 microg/gC) subjects, and no effect of living close to CA plants could be shown. Dental amalgam, chewing on amalgam, and fish consumption were positively associated with U-HgC. In subjects from the general population, no effects on the kidney markers could be detected, while in men, including workers occupationally exposed to mercury, U-HgC was positively associated with the kidney markers, especially with NAG, but to some extent also with A1M and albumin. Differences in urinary mercury and kidney markers in the general population between three studied countries could possibly be due to dietary factors, increased susceptibility to mercury at low selenium intake or co-exposure to other nephrotoxic metals.

We conducted a study within the framework of the interdisciplinary European Mercury Emission from Chloralkali Plants (EMECAP) project to assess exposure to mercury (Hg) and the contribution of Hg emissions from a mercury cell chloralkali plant to urinary mercury (U-Hg) in adults living near the plant. We collected data from questionnaires and first morning urine samples from 75 subjects living near the Tarnow plant in Poland and 100 subjects living in a reference area. Median U-Hg was 0.32 mug/g creatinine (microg/gC) and 0.20 microg/gC, respectively. The median U-Hg was also higher in the amalgam-free subjects living near the plant (0.26 microg/gC) than in the reference group (0.18 microg/gC), but no such association was found in a multivariate analysis. There was a statistically significant positive association between U-Hg and number of teeth with amalgams, a negative association with age and a tendency towards higher U-Hg in female subjects. In the amalgam-free subjects there were statistically significant effects of female sex and fish consumption, and a negative association with age. The additional long-term average air Hg concentration from the plant, based on EMECAP environmental measurements and modelling, was estimated to be 1-3.5 ng/m(3) for the residential study area and should have a very small effect on U-Hg. The other Hg emission sources such as coal combustion facilities located nearby should be taken into account in assessing the overall impact of air Hg on U-Hg in this area.

Hair mercury levels were determined in 143 individuals from households of members in angling societies in an area of Sweden with many lakes that have freshwater fish with relatively high mercury levels. Thus, the individuals had a potentially high intake of methyl mercury. The mean mercury concentration of pike and perch was approximately 0.7 microg/g. One-third of the subjects consumed these freshwater fish at least once a week. As could be expected, there was a clear increase in hair Hg with reported freshwater fish consumption (P < 0.001). The median mercury level in hair was 0.9 microg Hg/g for the whole group, and for those who reported consumption of freshwater fish at least once a week it was 1.8 microg/g. The highest hair mercury level was 18.5 microg/g, in a man who consumed pike and perch several times per week. Men had higher hair Hg than women, also when stratified for fish consumption. This was verified in 32 couples, of which the man and woman consumed the same fish and reported the same consumption. The median hair mercury level in these 32 couples was 1.3 microg/g for men and 0.8 microg/g for women (P = 0.002). About half of the subjects had hair mercury exceeding 1 microg/g, corresponding to the reference dose (RfD) of 0.1 microg of mercury per kilogram body weight set by the US Environmental Protection Agency. Although the RfD applies to all populations, the most at-risk group at these levels is pregnant women. There were only 2 women (of 12) of fertile age with hair mercury above 1 microg/g. In Sweden pregnant women are advised not to eat perch and pike at all during pregnancy. Since fish is rich in many important nutrients, it is unsatisfactory that fish consumption must be restricted, and thus there is a need to reduce mercury levels in fish.

Blood samples and questionnaire background data were collected from 96 children (age 2-14 years) living in urban, suburban, or rural areas with varying traffic intensity and industrial lead pollution in Uruguay. Spot samples of tap water were collected from the homes of 44 children, and samples of top soil were taken from seven areas. Samples of air-borne dust were collected in central and suburban Montevideo. Blood lead concentrations (B-Pb) in children ranged between 47 and 191 (mean 96) micrograms/L and exceeded in 36% of the children 100 micrograms/L, the intervention level adopted by the United States Centers for Disease Control. Lead in tap water ranged from 0.2 to 230 (mean 15) micrograms/L and exceeded in 39% of the samples the maximum level recommended by WHO, 10 micrograms/L. Lead pipes were used in parts of the water supply systems. Lead in air varied between different locations from 0.15 to 1.7 micrograms/m3, highest in the very center of Montevideo. The median soil lead ranged from 6 to 2100 micrograms/g and was highest in industrially polluted areas. At multiple regression analysis, B-Pb was significantly associated only with age (P = 0.032) and traffic intensity at school (P = 0.045). No significant impact on B-Pb of lead in water or soil could be established.

It has been shown in vitro that human oral and intestinal bacteria are able to methylate inorganic mercury (Hg) to methylmercury (MeHg). In vivo methylation has been reported for guinea pigs, and several studies have found higher levels of organic Hg in blood of workers exposed to inorganic Hg. In search for indications of in vivo methylation of Hg, we determined total Hg in urine (U), plasma (P), and erythrocytes (Ery), and MeHg in erythrocytes, in 22 chloralkali workers exposed to inorganic Hg, and in 22 age-matched referents. The subjects in both groups ate fish not more than once a week. MeHg was determined using ion exchange separation and cold vapor atomic absorption spectrometry. The mean concentrations of total mercury in chloralkali workers and referents were 26 vs 2.3 micrograms/g creatinine (U-Hg), 9.7 vs 1.8 ng/g (P-Hg), and 11.4 vs 5.6 ng/g (Ery-Hg). The mean Ery-MeHg concentrations were 3.0 vs 3.7 ng/g, and there were no correlations between Ery-MeHg on the one hand and U-Hg or P-Hg on the other. Our results indicate no significant in vivo methylation of inorganic Hg in man. Contradictory results from previous studies may be due either to bias owing to fish consumption or to analytical shortcomings.

Mercury (Hg) and protein levels in cerebrospinal fluid (CSF), and mercury in plasma (P), erythrocytes (Ery), and urine (U), were determined in 10 workers exposed to mercury vapor for 2-28 (median 13) years and in 16 occupationally unexposed referents. CSF-Hg was analyzed using radiochemical neutron activation analysis and P-Hg, Ery-Hg, and U-Hg were analyzed using cold-vapor atomic absorption spectrometry. P-Hg and U-Hg were significantly higher, but Ery-Hg was similar in the exposed workers (37 nmole/liter, 16 nmole/mmole creatinine, and 56 nmole/liter, respectively) compared with the referents (7.1 nmole/liter, 1.9 nmole/mmole creatinine, and 52 nmole/liter, respectively). CSF-Hg was correlated to P-Hg, and in workers with current high exposure (P-Hg > 50 nmole/liter), the CSF-Hg was significantly higher than in the reference group (1.08 versus 0.35 nmole/liter; P = 0.002). In two individuals, studied after ceased occupational exposure, a decrease of CSF-Hg was seen. There were no indications of changes in the CSF protein pattern in the exposed workers.

Levels of selenium and mercury in blood and urine were analysed in 37 male workers exposed to elemental mercury vapour in a chloralkali plant and in 39 unexposed controls of the same age. Mean urinary Hg was 223 nmol l-1 (15 nmol/mmol creatinine) in the exposed group and 26 nmol l-1 (2.0 nmol/mmol creatinine) in the controls. Mean blood and plasma Hg levels were 46 and 36 nmol l-1, respectively, in the exposed group, as compared with 17 and 7 nmol l-1 in the controls. The concentrations of Se in plasma and erythrocytes did not differ between the two groups. Urinary Se levels were, however, slightly but significantly lower in the exposed group (median values 23 vs 29 nmol/mmol creatinine), and there was a negative correlation between urinary Se and plasma Hg in the exposed group. This may be due to a retention of Se in the kidneys. In a subgroup of exposed workers and controls, glutathione peroxidase, superoxide dismutase and catalase were also analysed. No differences were found between the groups with respect to these antioxidative enzymes. The effect on Se status of moderate Hg exposure seems to be of minor clinical importance.