Contribution of PCB exposure from fish consumption to total dioxin-like dietary exposure

Polychlorinated biphenyls (PCB) are the second greatest cause of fish advisories, and are often the greatest contributors to dioxin-like toxic equivalency (TEQ) in fish and seafood. Because fish consumption is associated with both contaminant risks and health benefits, incremental health risks from PCBs in fish should be considered within the context of overall TEQ associated dietary risk to enable consumers to make informed decisions about choosing to eat fish or alternate foodstuffs. In this paper, potential TEQ exposure from PCBs in fish for adults with a variety of consumption patterns and consuming fish from a variety of sources are calculated using recent consumption and fish contaminant data from the literature and compared to total TEQ exposure from all sources. For high-level consumers and individuals eating fish from relatively contaminated sites, PCB TEQ exposure from fish consumption alone may exceed the 1 pg TEQ/kg/day average adult daily intake estimated by EPA, which itself carries an upper bound cancer risk of 1 in 1000. PCB TEQ risk for average consumers of commercial fish is expected to be far less, but is highly uncertain, since there is a dearth of congener specific PCB data for commercial fish and seafood.     

Mercury exposure monitoring for Korean schoolchildren: I. Influence of socioeconomic and demographic variables

The objective of this study was to determine the total Hg in both urine and blood samples and to investigate an association between Hg levels, and the socioeconomic and demographic factors (covariates) from school children of 7–13 years old (n=2,000) during 2005–2006. This paper was the first part of the twopart series. Part 1 introduced the effect of the factors in Hg level. The second part focused upon dietary habits, fish consumption (sources and frequency), smoking habits, alcohol consumption, residential location and other factors. The parameters in this study included parental age, income, parental educational level, and parental age at delivery. Average Hg levels in blood and urinary from both female and male subjects were 2.42±1.02 μg/L [Unit] (N=1,974) and 2.53±1.88 (N=1,528) μg/g-ct (corrected for creatinine), respectively. Moreover, total Hg levels in blood did not exceed guidelines of U. S. Environmental Protection Agency (USEPA) or the Commission of Human Biological monitoring (CHBM). Conclusively, statistical significance was elucidated between age of children and mercury levels in urine or blood. Levels of parental education also exerted a direct influence on Hg levels.     

Impact of a risk-benefit advisory on fish consumption and dietary exposure to methylmercury in France

We designed the CORAI (COnsumer Risk Advisory Inquiry) study to observe consumer reactions' after an advisory revealing risk of methylmercury contamination together with benefits of Long-Chain Poly Unsaturated Fatty Acids of the n-3 variety (LC n-3 PUFA). The message was very close to the ones commonly delivered by national food agencies and included recommendations for women of childbearing age and children below 15 years old. Two groups of subjects including consumers at risk were selected. Participants recorded the frequency of their fish consumption detailed by species for them and their family over a one-month period one month before, a month immediately after and 3 month after the advisory. Results were compared between consumers receiving the advisory and controls. Results show that the message revelation led to a significant decrease in total fish consumption which is greater for children below 6 years old than for the children between 6 and 15 years old and women. The consumption of the most contaminated fish quoted in the advisory, rarely consumed and poorly known by French consumers did not decrease in any group despite the advice to avoid their consumption. The consumption of other fish products quoted in the advisory but frequently consumed and better known, as canned tuna, did decrease and was a major contributor to the overall reduction of exposure for the advised group. Before the information, about 3% of women of childbearing age are exceeding the PTWI for MeHg and both the average and the high percentiles of the exposure to MeHg are decreasing significantly in the advised group. Regarding the number of subjects of the advised group exceeding the PTWI, they were 6, 3 and 2, respectively, in May, June and September. Accompanying questionnaires show that consumers imperfectly memorize most of the fish species quoted in the recommendation. This paper concludes that consumer advisory, which is a major tool for risk management, has a minimal effect under our experimental conditions to reduce the exposure of groups at risk. Messages to be carried to consumers should be carefully tested for long term memorization in order to become more effective.     

Mercury exposure in utero and during infancy

Mercury in blood samples was speicated from mothers and their infants up to 2 mo after delivery. There were significant correlations between umbilical cord blood and maternal blood for methylmercury (MeHg) and inorganic mercury (I-Hg) levels. The MeHg levels in cord blood were significantly higher than in maternal blood, while I-Hg levels were significantly higher than in maternal blood, while I-Hg levels were about the same. The maternal MeHg and I-Hg levels remained stable during the sampling period, whereas the MeHg concentration in infant blood decreased more than 45% between the 72-h and 2 mo sampling times. The I-Hg levels in infant blood were low at birth, and remained low during the sampling period. The results of the present study do not support I-Hg absorption through milk as a significant source of exposure. However, the number of observations is small, and a larger study is warranted in order to verify the data.     

Mercury, cadmium, lead and arsenic levels in three pelagic fish species from the Atlantic Ocean: Intra- and inter-specific variability and human health risks for consumption

Three commonly consumed and commercially valuable fish species (sardine, chub and horse mackerel) were collected from the Northeast and Eastern Central Atlantic Ocean in Portuguese waters during one year. Mercury, cadmium, lead and arsenic amounts were determined in muscles using graphite furnace and cold vapour atomic absorption spectrometry. Maximum mean levels of mercury (0.1715 ± 0.0857 mg/kg, ww) and arsenic (1.139 ± 0.350 mg/kg, ww) were detected in horse mackerel. The higher mean amounts of cadmium (0.0084 ± 0.0036 mg/kg, ww) and lead (0.0379 ± 0.0303 mg/kg, ww) were determined in chub mackerel and in sardine, respectively. Intra- and inter-specific variability of metals bioaccumulation was statistically assessed and species and length revealed to be the major influencing biometric factors, in particular for mercury and arsenic. Muscles present metal concentrations below the tolerable limits considered by European Commission Regulation and Food and Agriculture Organization of the United Nations/World Health Organization (FAO/WHO). However, estimation of non-carcinogenic and carcinogenic health risks by the target hazard quotient and target carcinogenic risk, established by the US Environmental Protection Agency, suggests that these species must be eaten in moderation due to possible hazard and carcinogenic risks derived from arsenic (in all analyzed species) and mercury ingestion (in horse and chub mackerel species).     

Contribution of fish consumption to heavy metals exposure in women of childbearing age from a Mediterranean country (Spain).

The concentrations of cadmium (Cd), lead (Pb) and mercury (Hg) were determined in samples from sword-fish (Xiphias gladius, n=37) and louvar (Luvarus imperialis, n=17) taken in an official surveillance programme in Madrid (Spain). The levels of heavy metals were measured by atomic absorption spectrophotometry (hydride generator for Hg and flame atomic absorption for Cd and Pb) after digestion of the samples (microwave digestion for Hg and drying chamber for Cd and Pb). Pb contamination was negligible in both species. Cd was detected in 89.19% of the samples from sword-fish and 52.94% from louver; 17.65% of louvar and none from sword-fish being higher than maximum residue limits (MRL). However, around 90% of louvar samples and around 35% of sword-fish portions exceeded MRL for Hg; around 30% of louvar samples having levels even higher than 1 microg/g. The consumption of one serving of 150 g either of louvar or sword-fish would not be relevant for Cd and Pb provisional tolerable weekly intake (PTWI) of these elements for women in childbearing age, but it would largely exceed the tolerable values for Hg.     

Management options to reduce exposure to methyl mercury through the consumption of fish and fishery products by the French population

This paper presents an updated assessment of exposure in France to methyl mercury through the consumption of fish and fishery products, and proposes several management scenarios which could reduce this exposure through changes to fish contamination levels or fish consumption patterns. The exposure model was applied in line with previous methodological results [Tressou, J., Crépet, A., Bertail, P., Feinberg, M.H., Leblanc J.Ch., 2004a. Probabilistic exposure assessment to food chemicals based on extreme value theory: application to heavy metals from fish and sea products. Food Chem. Toxicol. 42, 1349-1358; Tressou, J., Leblanc, J.Ch., Feinberg, M., Bertail, P., 2004b. Statistical methodology to evaluate food exposure to a contaminant and influence of sanitary limits: application to ochratoxin A. Regul. Toxicol. Pharmacol. 40, 252-263] so as to obtain a realistic estimate of probability and confidence intervals (95% CI) concerning French consumers exposed to levels exceeding the revised fixed provisional tolerable weekly intake (PTWI) for methyl mercury of 1.6 microg/week/kg of body weight, established by the Joint FAO/WHO Expert Committee on Food Additives in 2003. The results showed that young children aged between 3 and 6 years old or 7 and 10 years old, and women of childbearing age were at the risk groups. With respect to these groups and according to the fish consumers patterns (consumers of predatory fish only or consumers of predatory and nonpredatory fish), the results suggested that strategies to diminish MeHg exposure by reducing the amount of predatory fish consumed would be more efficient in significantly decreasing the probability of exceeding the PTWI than the implementation of international standards.     

Hair-to-blood ratio and biological half-life of mercury: experimental study of methylmercury exposure through fish consumption in humans

The hair-to-blood ratio and biological half-life of methylmercury in a one-compartment model seem to differ between past and recent studies. To reevaluate them, 27 healthy volunteers were exposed to methylmercury at the provisional tolerable weekly intake (3.4 μg/kg body weight/week) for adults through fish consumption for 14 weeks, followed by a 15-week washout period after the cessation of exposure. Blood was collected every 1 or 2 weeks, and hair was cut every 4 weeks. Total mercury (T-Hg) concentrations were analyzed in blood and hair. The T-Hg levels of blood and hair changed with time (p < 0.001). The mean concentrations increased from 6.7 ng/g at week 0 to 26.9 ng/g at week 14 in blood, and from 2.3 to 8.8 μg/g in hair. The mean hair-to-blood ratio after the adjustment for the time lag from blood to hair was 344 ± 54 (S.D.) for the entire period. The half-lives of T-Hg were calculated from raw data to be 94 ± 23 days for blood and 102 ± 31 days for hair, but the half-lives recalculated after subtracting the background levels from the raw data were 57 ± 18 and 64 ± 22 days, respectively. In conclusion, the hair-to-blood ratio of methylmercury, based on past studies, appears to be underestimated in light of recent studies. The crude half-life may be preferred rather than the recalculated one because of the practicability and uncertainties of the background level, though the latter half-life may approximate the conventional one.     

Comparison of pesticide exposure from consumption of domestic and imported fruits and vegetables

Estimates of daily dietary human exposure to 18 common pesticides found in fruits and vegetables were developed from residue data obtained from the 2003 US Food and Drug Administration’s Regulatory Monitoring Program using probabilistic dietary exposure modeling. The differences between the exposures from domestic versus imported fruit and vegetable residues were compared. Of the 15 pesticides for which quantifiable residues were detected from both domestic and imported fruit and vegetable samples, domestic exposures were significantly higher for 11 pesticides while imported exposures were higher for the remaining four. The five pesticides showing the highest exposures all demonstrated greater domestic exposures than imported exposures. The mean daily exposure estimate for one pesticide, methamidophos, was above the reference dose for domestic fruits and vegetables while slightly below the reference dose for imported fruits and vegetables. Exposures to the other 17 pesticides were well below the established reference doses for domestic and imported fruits and vegetables. Exposure from pesticides in domestic foods exceeds exposure from imported foods and demonstrates that probabilistic modeling of dietary exposure provides more useful information concerning the relative risks of domestic and imported foods than that obtained from the traditional comparisons of residue detection frequency and violation rates.     

Mercury exposure and its effects on fertility and pregnancy outcome

Mercury (Hg), a highly toxic environmental pollutant, shows harmfulness which still represents a big concern for human health, including hazards to fertility and pregnancy outcome. Research has shown that Hg could induce impairments in the reproductive function, cellular deformation of the Leydig cells and the seminiferous tubules, and testicular degeneration as well as abnormal menstrual cycles. Some studies investigated spontaneous abortion and complicated fertility outcome due to occupational Hg exposure. Moreover, there is a relation between inhaled Hg vapour and reproductive outcome. This MiniReview evaluates the hypothesis that exposure to Hg may increase the risk of reduced fertility, spontaneous abortion and congenital deficits or abnormalities.     

Health benefits and potential risks related to consumption of fish or fish oil

The nutritional benefits of fish consumption relate to the utilization of proteins of high biological value, as well as certain minerals and vitamins that fish provide. Fish or fish oil contains omega-3 polyunsaturated fatty acids (PUFAs) that appear to play several useful roles for human health. Conversely, some carcinogenic contaminants are also stored in the adipose tissue of fish. The objective of this paper is to evaluate the potential health benefits and risks related to the consumption of fish or fish oil. Health benefits related to the consumption of fish or omega-3 PUFAs were obtained by an extensive literature search. Potential health risks related to carcinogenic contaminants (e.g., dioxin, PCB, etc.) in fish were estimated using the U.S. EPA-approved cancer risk assessment guidelines. Potential health risk estimates were evaluated by comparing them with the acceptable excess risk level of 10(-6)-10(-4). Scientific data indicate that the consumption of fish or fish oil containing omega-3 PUFAs reduces the risk of coronary heart disease, decreases mild hypertension, and prevents certain cardiac arrhythmias and sudden death. Risk estimates in humans for carcinogenic environmental contaminants in fish ranged from an excess risk level of 3x10(-6)-9x10(-4). These risk estimates appeared to meet the acceptable excess risk level criteria. Therefore, consumption of fish in accordance with the State of Michigan Fish Advisory Guidelines is safe and should be encouraged. The top 11 fish species [e.g., sardines, mackerel, herring (Atlantic and Pacific), lake trout, salmon (Chinook, Atlantic, and Sockeye), anchovy (European), sablefish, and bluefish] provide an adequate amount of omega-3 PUFAs (2.7-7.5g/meal) and appear to meet the nutritional recommendation of the American Heart Association.     

Association between cigarette consumption and academic achievement in Korean adolescents

Aims: The purpose of this study was to examine whether smoking frequency and cigarette consumption are related to academic achievement in Korean adolescents. Method: Data from the Seventh Korea Youth Risk Behavior Web-based Survey (KYRBWS-VII) administered in 2011 were analyzed; 75,643 adolescents from the first year of middle school through the third year of high school participated in the survey. We used multivariate logistic regression analysis to investigate the association in question after adjusting for variables such as age, body mass index, frequency of drinking, frequency of breakfast consumption, parents’ education level, family economic status, mental stress and the frequency of vigorous physical activity (PA), moderate PA and muscular strength exercises. Results: The odds ratios (ORs) for achieving average or higher academic achievement in boys compared with those who never smoked and stratified by the frequency of smoking were as follows: 1–2 day(s) per month, 0.594 (p?<?0.001); 3–5 days per month, 0.571 (p?<?0.001); 6–9 days per month, 0.529 (p?<?0.001); 10–19 days per month, 0.472 (p?<?0.001); 20–29 days per month, 0.491 (p?<?0.001) and every day, 0.342 (p?<?0.001). For girls, the ORs for achieving average or higher academic achievement compared with those who never smoked and stratified by the frequency of smoking were as follows: 1–2 day(s) per month, 0.482 (p?<?0.001); 3–5 days per month, 0.409 (p?<?0.001); 6–9 days per month, 0.648 (p?=?0.037); 10–19 days per month, 0.723 (p?=?0.032); 20–29 days per month, 0.543 (p?<?0.001) and every day, 0.433 (p?<?0.001). The ORs in boys for achieving average or higher academic achievement compared with those who never smoked and stratified by cigarette consumption were as follows: <1 cigarette per day, 0.656 (p?<?0.001); 1 cigarette per day, 0.541 (p?<?0.001); 2–5 cigarettes per day, 0.446 (p?<?0.001); 6–9 cigarettes per day, 0.375 (p?<?0.001); 10–19 cigarettes per day, 0.281 (p?<?0.001) and ≥20 cigarettes per day, 0.340 (p?<?0.001). For girls, the ORs for achieving average or higher academic achievement compared with those who never smoked and stratified by cigarette consumption were as follows: <1 cigarette per day, 0.550 (p?<?0.001); 1 cigarette per day, 0.507 (p?<?0.001); 2–5 cigarettes per day, 0.549 (p?<?0.001); 6–9 cigarettes per day, 0.356 (p?<?0.001); 10–19 cigarettes per day, 0.353 (p?<?0.001) and ≥20 cigarettes per day, 0.729 (p?=?0.242). Conclusion: There are certain indicators that smoking negatively influences educational achievement in Korean adolescents. To improve academic achievement, it is recommended that adolescents do not smoke.     

Characteristics and factors of alcohol consumption among Korean male workers

This article aims to assess the hypothesis of Charlton & Bates about a negative correlation between cigarette smoking and mobile phone ownership among adolescents. This hypothesis is discussed and tested by using data from a national survey conducted in France in 2000 (n = 8414; age 17). The results show that, in France, owning a mobile phone is positively correlated with smoking, and this relationship remains significant once confounding factors are controlled. Thus, cigarette smoking and mobile phone ownership could turn out to be complementary rather than substitutable goods or could be considered as two characteristics of the same lifestyle.     

Mercury distribution in the rat brain after mercury vapor exposure.

Brown Norwegian rats were exposed to mercury vapor at a concentration of approximately 1 mg/m3 for 5 weeks 24 hr/day 7 days a week and 6 hr/day 3 days a week, respectively. The total mercury absorption was calculated to 264 and 35 micrograms per week and 100 g body weight. The mean blood mercury concentration was 0.25 +/- 0.03 and 0.09 +/- 0.01 microgram/g, and the total concentration in the brain was 5.03 +/- 0.73 and 0.71 +/- 0.10 microgram/g tissue, respectively. The mercury distribution in the brains was examined using a method based on chemographic principles. Mercury was found primarily in the neocortex, in the basal nuclei, and in the cerebellar Purkinje cells. This distribution pattern corresponded to the pattern of inorganic mercury described after exposure to methyl mercury. Distribution of mercury after administration of different mercury compounds is discussed.     

Mercury temporal trends in top predator fish of the Laurentian Great Lakes

Mercury (Hg) contamination is widespread in the Laurentian Great Lakes region and is a serious environmental concern. In anaerobic environments such as lake sediments, mercury is transformed into methylmercury (MeHg) and can biomagnify up the food chain to toxic concentrations. The Great Lakes Fish Monitoring Program (GLFMP), administered by the US EPA Great Lakes National Program Office (GLNPO), aims to monitor temporal trends of mercury in the five Great Lakes using top predator fish as biomonitors. Total Hg (THg) concentrations were measured in Great Lake fish collected between 1999 and 2009. Single factor ANOVA determined that average fish THg concentrations over this time period in the five lakes were significantly different from one another in the order of Superior > Huron > Michigan > Ontario > Erie. By fitting the data to three different models (linear, quadratic, and two-segment piecewise), it was determined that Hg concentrations in top predator fish (lake trout, or walleye in Lake Erie) are currently increasing in Lake Erie and the Apostle Island sampling site in Lake Superior. Significant decreasing trends are evident in Lakes Michigan, Ontario, and the Rockport sampling site in Lake Huron, although all of the lakes exhibit elevated concentrations in fish compared to historic concentrations. As new Hg emission controls are implemented in the US, continued monitoring of Hg in Great Lakes fish will be needed to determine if they influence the current concentrations and trends.     

Human exposure to PCDD/Fs and PCBs through consumption of fish and seafood in Catalonia (Spain): Temporal trend

The concentrations of PCDD/Fs and 18 PCBs (DL- and NDL-) were analyzed in 16 fish and seafood species widely consumed in Catalonia (Spain). The exposure of these pollutants was subsequently estimated according to various groups of population. The concentrations of PCDD/Fs and PCBs showed an important decrease in relation to the baseline study (2000) and our last survey (2008). Sardine and red mullet were the species showing the highest pollutant concentrations, while canned tuna and cuttlefish presented the lowest levels. Sardine was the main contributor to the exposure of PCDD/Fs and PCBs. In contrast, swordfish was the species with the lowest contribution to the exposure of PCDD/Fs, DL-PCBs, and PCDD/Fs+DL-PCBs, while clam was the minor contributor for NDL-PCBs and total PCBs. For all groups of population, the current intakes of PCDD/Fs and PCBs were lower than the TDI (1–4 pg WHO-TEQ/kg body weight/day), being children the group with the highest exposure. However, this exposure should not mean a health risk for this group of population. The current intake of PCDD/Fs and PCBs through fish and seafood consumption was similar or even lower than most values reported in recent studies all over the world.     

Relationship between toxicant transfer kinetic processes and fish oxygen consumption

Three organic compounds of different hydrophobicity, 1,2,4,5-tetrachlorobenzene (TeCB), 3,4,5,6-tetrachloroguaiacol (TeCG) and 4,6-dichlorobenzenediol (DBD), were chosen as the test chemicals to carry out a series of investigations to look at the relationship between toxicant transfer and fish metabolic rate. A significant correlation was found between the toxicant uptake rate constant (k(1)) and fish oxygen consumption, regardless of fish size and species. This correlation was improved when fish toxicant body load was expressed on a percent body lipid basis. Similarly, there also existed a significant relationship between the toxicant depuration rate constant (k(2)) and fish oxygen uptake for a range of chemicals with different octanol/water partition coefficients (K(ow)).     

Arsenic exposure and tobacco consumption: Biomarkers and risk assessment

Arsenic is measurable in tobacco and cigarette mainstream smoke (MSS). Whether arsenic has an independent role in diseases associated with tobacco consumption is not known. Epidemiology and biomonitoring data and probabilistic risk assessment (PRA) methods were used to investigate this potential association. Analysis of data from the National Health and Nutrition Examination Survey (NHANES) showed that urine arsenic concentrations in tobacco consumers were not different or were lower than levels in non-consumers of tobacco. Additionally, urine arsenic levels from NHANES tobacco consumers were five-times or more lower than levels reported in epidemiology studies to be associated with adverse health effects. Results of PRA indicated that mean non-cancer hazard estimates and mean incremental lifetime cancer risk estimates were within accepted ranges. Taken together, these results suggest that arsenic may not be independently associated with tobacco consumption or diseases related to tobacco consumption.     

Cadmium exposure and tobacco consumption: Biomarkers and risk assessment

To investigate whether cadmium has an independent role in diseases associated with tobacco consumption, epidemiology data were reviewed, biomonitoring data were analyzed, and probabilistic risk assessment (PRA) was performed. Results from previous epidemiology studies have indicated that there are adverse health effects potentially in common between cadmium exposure and tobacco consumption. Analysis of publically available biomonitoring data showed that blood (B–Cd) and urine (U–Cd) cadmium were higher in cigarette smokers compared with smokeless tobacco (SLT) consumers, and B–Cd and U–Cd in SLT consumers were not significantly different than in non-consumers of tobacco. Comparison with previously established biomonitoring equivalent (BE) values indicated that B–Cd and U–Cd in the majority of these cigarette smokers and SLT consumers did not exceed the blood and urine BEs. Results of the PRA showed that the mean hazard estimate was below a generally accepted regulatory threshold for SLT consumers, but not for cigarette smokers. In total, this evaluation indicated that cadmium exposures in tobacco consumers differed by product category consumed; cadmium in tobacco may not be associated with tobacco consumption related diseases; if cadmium in tobacco contributes to tobacco consumption related diseases, differences in hazard and/or risk may exist by product category.