Urinary 1-hydroxypyrene and PAH exposure in 4-year-old Spanish children

Aims:

Exposure to polycyclic aromatic hydrocarbons (PAH), among the main compounds present in polluted urban air, is of concern for children's health. Childhood exposure to PAH was assessed by urinary monitoring of 1-hydroxypyrene (1-OHP), a pyrene metabolite, investigating its association with exposure to air pollution and other factors related to PAH in air.

Methods:

A group of 174 4-year-old children were recruited and a questionnaire on their indoor and outdoor residential environment was completed by parents. At the same time, environmental measurements of traffic-related air pollution (NO₂) were carried out. A urine sample was collected from each child in order to analyze 1-OHP using HPLC with fluorescence detection, correcting for creatinine concentrations. Non-parametric tests and regression analyses were used to identify environmental factors that influence 1-OHP excretion.

Results:

Mean urinary 1-OHP concentration was 0.061 μmol/mol creatinine, ranging from 0.004 to 0.314 μmol/mol. Non-parametric tests and regression analysis showed positive and significant associations (P ≤ 0.05) between 1-OHP and predicted residential exposure to NO₂ (which was based on outdoor environmental measurements and geo-statistical analysis), self-reported residential vehicle traffic, passive smoking and cooking appliance. 1-OHP levels tended to be higher among children living in urban areas (0.062 μmol/mol vs. 0.058 μmol/mol for children living in rural areas) but differences were not significant (P = 0.20).

Conclusion:

In Southern Spain, concentrations of urinary 1-OHP were in the lower range of those generally reported for children living in non-polluted areas in Western Europe and the USA. Traffic-related air pollution, passive smoking and cooking appliance influenced urinary 1-OHP level in the children, which should be prevented due to the health consequences of the inadvertent exposure to PAH during development.     

Exposure assessment of PM2.5 and urinary 8-OHdG for diesel exhaust emission inspector

Animal studies have shown exposure to diesel exhaust particles (DEPs) to induce production of reactive oxygen species (ROSs) and increase levels of 8-hydroxydeoxyquanosine (8-OHdG). Controversial results have been obtained regarding the effects of workplace exposure on urinary 8-OHdG level. This study assessed concentrations of environmental PM_2.5 in DEP (DEP_2.5), personal DEP_2.5 and urinary 8-OHdG of diesel engine exhaust emission inspector (inspector) at a diesel vehicle emission inspection station (inspection station). The analysis specifically focuses on the factors that influence inspector urinary 8-OHdG. Repeated-measures study design was used to sample for five consecutive days. A total of 25 environmental PM_2.5 measurements were analyzed at 5 different locations by using a dichotomous sampler, and a total of 55 personal PM_2.5 measurements were analyzed from inspectors by using PM_2.5 personal sampler. During the sampling period, a total of 110 pre- and post-work urine samples from inspectors, and 32 samples from the control group were collected. Following age and sex matching between the inspectors and the control group, levels of urinary 8-OHdG were analyzed.Environmental and personal concentrations of DEP_2.5 were 107.25 ± 39.76 (mean ± SD) and 155.96 ± 75.70 μg/m³, respectively. Also, the concentration of urinary 8-OHdG differed significantly between inspector and control non-smokers, averaging 14.05 ± 12.71 and 6.58 ± 4.39 μg/g creatinine, respectively. Additionally, urinary 8-OHdG concentrations were associated with diesel exposure after controlling for smoking and cooking at home. Compared with the control group, the inspector displayed significantly increased levels of urinary 8-OHdG. Diesel exhaust is the single pollutant involved in the exposure of DEP_2.5 at the inspection station, as confirmed by the final results.     

Urinary BTEX, MTBE and naphthalene as biomarkers to gain environmental exposure profiles of the general population

The aim of this work was to evaluate urinary benzene, toluene, ethylbenzene, m+p-xylene, o-xylene (BTEX), methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), and naphthalene (NAP) as biomarkers of exposure to environmental pollutants. Personal air and urine samples from 108 subjects belonging to the Italian general population were compared. Urinary profiles were obtained by headspace gas chromatography-mass spectrometry. BTEX, MTBE, ETBE and NAP median airborne exposures during a 5-h sampling were 4.0, 25.3, 3.8, 9.3, 3.4, 3.4, < 0.8, and 3.4 µg/m³, respectively. Meanwhile, median urinary levels, as geometric means of three determinations were: 122, 397, 74, 127, 43, 49, < 15, and 46 ng/L, respectively. Urinary benzene and toluene concentrations were 4.6- and 1.2-fold higher in smokers than in non-smokers. For most chemicals, significant positive correlations between airborne exposure (log-transformed) and the corresponding biological marker (log-transformed) were found, with Pearson's r values for correlation, ranging from 0.228 to 0.396. Multiple linear regression analysis showed that the urinary level of these chemicals was influenced by personal airborne exposure, urinary creatinine, and urinary cotinine, with R² 0.733 for benzene. Urinary chemicals are useful biomarkers of environmental exposure. Given the ease of rapidly obtaining urine samples, they represent a non-invasive alternative to blood chemical analysis. The possibility of obtaining urinary exposure profiles makes this method an appealing tool for environmental epidemiology.     

Biomarkers of exposure to passive smoking of school children: frequency and determinants

This study aims to assess the extent of children' exposure to ETS and quantify potential determinants. A total of 2767 children aged 5-14 years participated in an environmental survey in East Germany in 1998-1999 (participation rate 75.9%). A subgroup of 979 children between the ages of 11 and 14 years with complete data on nicotine and cotinine in urine were selected for this analysis. This study population consisted of 73 self-reported smokers (7.5%), 793 non-smokers (81%) and 113 children with missing data on smoking status (11.5%). Nicotine and cotinine concentrations in spontaneous urine sample were determined by high-performance liquid chromatography methods with ultraviolet-detection and corrected for creatinine. Approximately 40% of self-reported non-smokers were exposed to environmental tobacco smoke (ETS) at home. Non-smoking children exposed to parental tobacco smoke at home compared with not exposed showed in average higher nicotine and cotinine concentration (geometric mean 4.7 microg/l vs. 1.4 microg/l and 8.1 microg/l vs. 2.7 microg/l) and the adjusted odds ratio (OR) for detectable biomarkers ranged between 17 and 22. There were increased rates of detectable biomarkers in urine with increasing numbers of smoked cigarettes in the household (adjusted OR increased from 8 to 54). Maternal smoking showed a stronger effect than paternal smoking. Furthermore, low parental education, cold season, height of dwelling (相似文献   

Total blood mercury, plasma homocysteine, methylmalonic acid and folate in US children aged 3-5 years, NHANES 1999-2004

Background

Mercury is a known neurotoxicant; however, the relationship between childhood exposures and neurodevelopmental outcomes is uncertain, and may be modified by nutrition-related susceptibilities. In vitro studies found that mercury inhibited methionine synthase, an enzyme that interacts with vitamin B-12 and folate to regenerate the amino acid methionine from homocysteine, and inhibition of methionine synthase diverted homocysteine to cysteine and glutathione synthesis. The relationships between mercury, homocysteine, B-12, and folate have not been examined in children.

Objective

This study aimed to evaluate associations between Hg and homocysteine in male and female children differentiated by higher and lower methylmalonic acid (MMA, an indicator of vitamin B-12 deficiency) and folate status.

Design

Cross-sectional data on total blood mercury (Hg), plasma homocysteine, MMA, and serum folate were obtained from the 1999-2004 National Health and Nutrition Examination Surveys for children aged 3-5 years (n = 1005). We used multiple linear regression to evaluate relationships between homocysteine and Hg quartiles, stratified by sex, MMA ≥ and folate < sample medians, adjusted for demographic, anthropometric, and environmental factors.

Results

In boys with higher MMA and lower folate (n = 135), but not in other children, we observed inverse associations between homocysteine and Hg. Children with Hg > 3.49 μmol/L showed 1.14 μmol/L lower homocysteine (p < 0.001) relative to the lowest quartile (≤ 0.70 μmol/L) {p-value for trend < 0.001}. Compared to other subsamples, this subsample had significantly higher homocysteine levels.

Conclusion

Hg was inversely correlated with plasma homocysteine in young boys, but not girls, with higher MMA and lower folate. Additional studies are merited to evaluate Hg and amino acid metabolism in susceptible children.     

Biomonitoring of benzene and 1,3-butadiene exposure and early biological effects in traffic policemen

The objective of this study was to determine benzene and 1,3-butadiene exposure through ambient air and personal air monitoring, as well as through biomarkers of exposure, and to evaluate the potential health risk of exposure through the use of biomarkers of early biological effects in central Bangkok traffic policemen. Ambient air concentrations of benzene and 1,3-butadiene at the roadsides were significantly higher than in police offices used as control sites (p < 0.001). Traffic policemen had a significantly higher exposure to benzene (median 38.62 μg/m³) and 1,3-butadiene (median 3.08 μg/m³) than office policemen (median 6.17 μg/m³ for benzene and 0.37 μg/m³ for 1,3-butadiene) (p < 0.001). Biomarkers of benzene exposure, blood benzene, and urinary metabolite, trans, trans-muconic acid were significantly higher in traffic policemen than office policemen (p < 0.001). No significant difference between traffic and office policemen was found in urinary benzene metabolite, S-phenyl mercapturic acid, or in urinary 1,3-butadiene metabolite, monohydroxy-butenyl mercapturic acid. Biomarkers of early biological effects, 8-hydroxy-2′-deoxyguanosine in leukocytes (8-OHdG), DNA-strand breaks, and DNA-repair capacity, measured as an increase in gamma ray-induced chromosome aberrations were significantly higher in traffic policemen than controls (p < 0.001 for 8-OHdG, p < 0.01 for tail length, p < 0.001 for olive tail moment, p < 0.05 for dicentrics and p < 0.01 for deletions). Multiple regression model including individual exposure, biomarkers of exposure, ages and years of work as independent variables showed that only the levels of individual 1,3-butadiene exposure were significantly associated with 8-OHdG and olive tail moment at p < 0.0001 indicating more influence of 1,3-butadiene on DNA damage. These results indicated that traffic policemen, who are exposed to benzene and 1,3-butadiene at the roadside in central Bangkok, are potentially at a higher risk for development of diseases such as cancer than office policemen.     

Mercury exposure and oxidative stress in communities of the Brazilian Amazon

This study was designed to assess possible associations between biomarkers of mercury (Hg) exposure and oxidative stress in fish-eating Amazonian communities. Clinical samples were obtained from riparians living in the Brazilian Amazon. Biomarkers of oxidative stress (glutathione - GSH, glutathione peroxidase - GSH-Px, catalase - CAT, activity and reactivation index of δ-aminolevulinate dehydratase - ALA-D (R%) were determined in blood. Total Hg was measured in whole blood (B-Hg), plasma (P-Hg) and hair (H-Hg). Association between biomarkers of Hg exposure and oxidative stress were examined using multiple regression models, including age, gender, alcohol consumption, smoking status, fish consumption and then stratified for gender. Significant inverse relations were observed between GSH-Px, GSH, CAT, ALA-D activity and B-Hg or H-Hg (p < 0.05). ALA-D reactivation index was positively related to B-Hg (p < 0.0001). P-Hg was directly related to ALA-D reactivation index and inversely associated with GSH-Px, GSH, and ALA-D activity (p < 0.05). When stratified for gender, women showed significant inverse associations between all biomarkers of Hg exposure and CAT (p < 0.05) or GSH (p < 0.05), while for men only P-Hg showed a significant inverse relation with GSH (p < 0.001). Our results clearly demonstrated an association between Hg exposure and oxidative stress. Moreover, for B-Hg, P-Hg and H-Hg gender differences were present.     

Aflatoxin and PAH exposure biomarkers in a U.S. population with a high incidence of hepatocellular carcinoma

The incidence of hepatocellular carcinoma (HCC) is significantly elevated in a Hispanic community in Bexar County, Texas. Chronic exposure to dietary aflatoxins (AFs) is a major risk factor for HCC; increased risk has been linked to polycyclic aromatic hydrocarbon (PAH) co-exposure and hepatitis virus infection. The aims of this study were to assess AF and PAH exposures, investigate dietary factors that may contribute to increased AF exposure, and determine the prevalence of hepatitis virus infection in Bexar Co. Blood and urine samples were collected from 184 volunteers for biomarker analyses and hepatitis screening. Serum AFB₁-lysine adduct, urinary AFM₁ and 1-hydroxypyrene (1-OHP) levels were measured using high-performance liquid chromatography. The average AFB₁-lysine adduct level detected in 20.6% of serums was 3.84 ± 3.11 pg/mg albumin (range 1.01-16.57 pg/mg). AFM₁ was detected in 11.7% of urines, averaging 223.85 ± 250.56 pg/mg creatinine (range 1.89-935.49 pg/mg). AFM₁ detection was associated with increased consumption of corn tortillas (p = 0.009), nuts (p = 0.033) and rice (p = 0.037). A significant difference was observed between mean 1-OHP values of non-smokers (0.07 ± 0.13) and smokers (0.80 ± 0.68) μmol/mol creatinine (p < 0.01). A high hepatitis C virus positivity rate (7.1%) was observed. Findings suggest that the incidence and level of AF and PAH exposure were less than those observed in a high-risk population; however, participants consuming higher amounts of foods prone to AF contamination may be more vulnerable to exposure and interactions with other environmental/biological factors (i.e., HCV).     

Interactions between endogenous and dietary antioxidants against Pb-induced oxidative stress in wild ungulates from a Pb polluted mining area

Certain physiologic disorders, attributed to lead (Pb) exposure are related to the generation of oxidative stress. Organisms rely on a complex antioxidant system, composed of endogenously produced compounds such as glutathione (GSH), superoxide dismutase (SOD) and GSH peroxidase (GPX); and dietary antioxidants such as vitamins A and E. The aim of this work was to study the interactions between both groups of antioxidants and to evaluate their role in fighting Pb-induced oxidative stress in wild ungulates living in a Pb mining area. We studied red deer (n = 54) and wild boar (n = 60) from mining and control sites. Liver Pb, copper (Cu) and selenium (Se) levels were measured in liver and bone. Levels of GSH, oxidized GSH (GSSG), lipid peroxidation (TBARS), α-tocopherol, free retinol and retinyl esters, and the activities of SOD and GPX were measured in liver. Wild boar and red deer from the mining sites had higher bone (geometric means: 7.36 vs. 1.23 μg/g dw for boar; and 0.46 vs. 0.11 μg/g dw for deer) and liver Pb levels (0.81 vs. 0.24 μg/g dw for boar; and 0.35 vs. 0.11 μg/g dw for deer) than the controls. Pb exposure in deer was associated with lower GSH, α-tocopherol and retinyl esters, and higher free retinol and TBARS. A similar effect on vitamin A balance was observed in wild boar, but this was accompanied with an increase in GSH and α-tocopherol. GPX activity and Se levels were higher in wild boar (mean in controls: 670 IU/mg protein and 1.3 μg/g dw, respectively) than in red deer (150 IU/mg protein and 0.3 μg/g). These differences may indicate that red deer is more sensitive to Pb-induced oxidative stress than wild boar. Both endogenous and nutritional antioxidants may be negatively affected by Pb exposure, and their interactions are essential to fight against Pb-mediated oxidative damage.     

Elevated levels of selenium in the typical diet of Amazonian riverside populations

Selenium (Se) intake is generally from food, whose Se content depends on soil Se and plant accumulation. For humans, adequate Se intake is essential for several selenoenzymes. In the Lower Tapajós region of the Brazilian Amazon, Se status is elevated with large inter-community variability. Se intake in this region, where Hg exposure is among the highest in the world, may be important to counteract mercury (Hg) toxicity.The present study was conducted in 2006 with 155 persons from four communities of the Lower Tapajós. The objectives were: i) to evaluate Se content in their typical diet and drinking water; ii) to compare food Se concentrations with respect to geographic location; and iii) to examine the contribution of consumption of different food items to blood Se.More than 400 local foods and 40 drinking water samples were collected. Participants responded to an interview-administered food frequency questionnaire and provided blood samples. Food, water and blood Se levels were assessed by ICP-MS. Since Brazil nuts may also contain significant levels of barium (Ba) and strontium (Sr), these elements were likewise analyzed in nuts.The highest Se concentrations were found in Brazil nuts, but concentrations were highly variable (median: 13.9 µg/g; range: 0.4-158.4 μg/g). Chicken, game meat, eggs and beef also contained considerable levels of Se, with median concentrations from 0.3 to 1.4 μg/g. There was no particular geographic distribution of food Se. Se concentration in drinking water was very low (< 1.4 µg/L). Blood Se covered a (103-1500 μg/L), and was positively related to regular consumption of Brazil nuts, domestic chicken and game meat. Brazil nuts were found to contain highly variable and often very high concentrations of Ba (88.0 µg/g, 1.9-1437 µg/g) and Sr (38.7 µg/g, 3.3-173 µg/g).Further studies should address multiple nutrient/toxic interactions in the diet and related effects on health.     

Dietary exposure and biomarkers of arsenic in consumers of fish and shellfish from France

Seafood, especially fish, is considered as a major dietary source of arsenic (As). Seafood consumption is recommended for nutritional properties but contaminant exposure should be considered. The objectives were to assess As intake of frequent French seafood consumers and exposure via biomarkers. Consumptions of 996 high consumers (18 and over) of 4 coastal areas were assessed using a validated food frequency questionnaire. Seafood samples were collected according to a total diet study (TDS) sampling method and analyzed for total As, arsenite (AsIII), arsenate (AsV), arsenobetaïne (AsB), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA). The average As dietary exposure is 94.7 ± 67.5 μg/kg bw/week in females and 77.3 ± 54.6 μg/kg bw/week in males (p < 0.001) and the inorganic As dietary exposure is respectively 3.34 ± 2.06 μg/kg bw/week and 3.04 ± 1.86 μg/kg bw/week (p < 0.05).Urine samples were collected from 382 of the subjects. The average urinary As concentration is 94.8 ± 250 μg/g creatinine for females and 59.7 ± 81.8 μg/g for males (p < 0.001). Samples having an As concentration above 75 μg/g creatinine (n = 101) were analyzed for inorganic As (As(III), As(V), MMA(V) and DMA(V)) which was 24.6 ± 27.9 μg/g creatinine for males and 27.1 ±20.6 μg/g for females. Analyses do not show any correlation between dietary exposure and urinary As.These results show that biological results should be interpreted cautiously. Diet recording seems to be the best way to assess dietary As exposure. Seafood is a high source of As exposure but even among high consumers it is not the main source of toxic As. From a public health point of view these results should be interpreted carefully in the absence of international consensus on the health-based guidance value.     

Organochlorine pesticides, polychlorinated biphenyls and trace elements in wild European sea bass (Dicentrarchus labrax) off European estuaries

Polychlorinated biphenyls (PCBs) and organochlorine pesticides like dichloro-diphenyl-trichloroethane (DDTs), hexachlorocyclohexanes (HCHs), aldrin, dieldrin and trace elements (Cd, Cu, Se, Pb, Zn and Hg) were analysed in the muscle of European sea bass (Dicentrarchus labrax) sampled in Atlantic coastal regions near several important European river mouths (Gironde, Charente, Loire, Seine and Scheldt). High contamination levels were measured in the muscles of European sea bass sampled in the coastal regions near those river mouths (e.g. Σ ICES PCB = 133-10,478 μg kg^− 1 lw and Hg = 250-2000 μg kg^− 1 dw).The Scheldt and the Seine are still among the most contaminated estuaries in Europe. Each region presented their specific contamination patterns reflecting different sources due to the input of the respective rivers. As fish and fishery products are the main contributors of the total dietary intake of organochlorinated pollutants, regular consumption of European sea bass with the reported contamination levels may represent a significant exposure route for the general human population.     

Dermal uptake of nicotine from air and clothing: Experimental verification

This study aims to elucidate in greater detail the dermal uptake of nicotine from air or from nicotine‐exposed clothes, which was demonstrated recently in a preliminary study. Six non‐smoking participants were exposed to gaseous nicotine (between 236 and 304 μg/m³) over 5 hours while breathing clean air through a hood. Four of the participants wore only shorts and 2 wore a set of clean clothes. One week later, 2 of the bare‐skinned participants were again exposed in the chamber, but they showered immediately after exposure instead of the following morning. The 2 participants who wore clean clothes on week 1 were now exposed wearing a set of clothes that had been exposed to nicotine. All urine was collected for 84 hours after exposure and analyzed for nicotine and its metabolites, cotinine and 3OH‐cotinine. All participants except those wearing fresh clothes excreted substantial amounts of biomarkers, comparable to levels expected from inhalation intake. Uptake for 1 participant wearing exposed clothes exceeded estimated intake via inhalation by >50%. Biomarker excretion continued during the entire urine collection period, indicating that nicotine accumulates in the skin and is released over several days. Absorbed nicotine was significantly lower after showering in 1 subject but not the other. Differences in the normalized uptakes and in the excretion patterns were observed among the participants. The observed cotinine half‐lives suggest that non‐smokers exposed to airborne nicotine may receive a substantial fraction through the dermal pathway. Washing skin and clothes exposed to nicotine may meaningfully decrease exposure.     

Long-term human exposure to lead from different media and intake pathways

Lead (Pb) is well known as an environmental pollutant: it can accumulate in various media, so actual lead exposure reflects both historical and present contaminations. Two main challenges then emerge: obtaining updated information to gain an overall picture of the sources of exposure, and predicting the resulting internal body exposure levels and effects that occur under long-term exposure conditions. In this paper, a modeling approach is used to meet these challenges with reference to Danish exposure conditions. Levels of lead content in various media have been coupled with data for lead intake and absorption in the human body, for both children and adults. An age-dependent biokinetic model allows then for determination of the blood lead levels resulting from chronic exposure. The study shows that the actual intake of lead is up to 27% of the Provisional Tolerable Daily Intake (PTDI) for children and around 8% for adults. It is confirmed that the critical route of exposure is via ingestion, accounting for 99% of total lead intake, while inhalation contributes only to 1% of total lead intake. The resulting lead levels in the blood after 2 years of exposure to actual contamination conditions have been estimated as up to 2.2 μg/dl in children and almost 1 μg/dl in adults. Impacts from lead can occur even at such levels. The role of historical and present sources to lead in the environment is discussed, and, for specific child and adult exposure scenarios, external-internal concentration relationships for the direct linkage between lead in environmental media and resulting concentrations of lead in blood are then presented.     

Sources of cadmium exposure among healthy premenopausal women

Background

Cadmium, a persistent and widespread environmental pollutant, has been associated with kidney function impairment and several diseases. Cigarettes are the dominant source of cadmium exposure among smokers; the primary source of cadmium in non-smokers is food. We investigated sources of cadmium exposure in a sample of healthy women.

Methods

In a cross-sectional study, 191 premenopausal women completed a health questionnaire and a food frequency questionnaire. The cadmium content of spot urine samples was measured with inductively-coupled plasma mass spectrometry and normalized to urine creatinine content. Multivariable linear regression was used to estimate the strength of association between smoking habits and, among non-smokers, usual foods consumed and urinary cadmium, adjusted for age, race, multivitamin and supplement use, education, estimated total energy intake, and parity.

Results

Geometric mean urine creatinine-normalized cadmium concentration (uCd) of women with any history of cigarette smoking was 0.43 μg/g (95% confidence interval (CI): 0.38-0.48 μg/g) and 0.30 μg/g (0.27-0.33 μg/g) among never-smokers, and increased with pack-years of smoking. Analysis of dietary data among women with no reported history of smoking suggested that regular consumption of eggs, hot cereals, organ meats, tofu, vegetable soups, leafy greens, green salad, and yams was associated with uCd. Consumption of tofu products showed the most robust association with uCd; each weekly serving of tofu was associated with a 22% (95% CI: 11-33%) increase in uCd. Thus, uCd was estimated to be 0.11 μg/g (95% CI: 0.06-0.15 μg/g) higher among women who consumed any tofu than among those who consumed none.

Conclusions

Cigarette smoking is likely the most important source of cadmium exposure among smokers. Among non-smokers, consumption of specific foods, notably tofu, is associated with increased urine cadmium concentration.     

Whole blood, serum, and saliva lead concentrations in 6- to 8-year-old children

With increasing evidence of adverse health effects of lower lead levels (below 10 µg/dL in whole blood), studies on novel internal dose biomarkers are needed. This study aimed at: (1) assessing the lead exposure by measuring this element in whole blood (Pb-blood), serum (Pb-serum), and 3 different types of saliva: whole (Pb-whole-saliva), submandibular/sublingual (Pb-sub-saliva) and parotid saliva (Pb-parotid-saliva); (2) correlating Pb-blood with Pb-serum; and (3) relating Pb-blood and Pb-serum with the lead found in the different salivas. The study population included 444 children aged 6 to 8 years attending 4 government schools in the district of Campos Eliseos, in Ribeirao Preto, Sao Paulo State, Brazil. Whole blood, serum, parotid, submandibular/sublingual (“sub-saliva”), and whole saliva were collected in trace element-free tubes. Lead concentrations were determined by inductively coupled plasma-mass spectrometry (ICP-MS). Median Pb-blood and Pb-serum were 2.1 µg/dL and 0.4 µg/L, respectively. Ten percent of the children had Pb-blood between 4.0 and 9.4 µg/dL. Boys showed higher Pb-blood than girls (2.3 vs. 2.0 µg/dL, p < 0.0003). Lead concentrations in whole, sub, and parotid saliva were 1.7, 1.4, and 1.3 µg/L, respectively. No significant correlations were found between Pb-blood and Pb-serum, between Pb-blood and lead in the 3 different salivas, or between Pb-serum and Pb-whole-saliva or Pb-sub-saliva. However, there was a weak statistically significant correlation between Pb-serum and Pb-parotid-saliva. In conclusion, the mean Pb-blood concentration was 2.4 µg/dL, with 10% of the children exhibiting Pb-blood between 4.0 and 9.4 µg/dL. Boys presented higher Pb-blood. Results suggest that Pb-blood has no correlation with Pb-serum or lead in the 3 different salivas collected here. A weak but statistically significant correlation between Pb-serum and Pb-parotid-saliva was found. Our results also point to the need for carrying out more studies on sources of exposure and lead levels in children in Brazil.     

Uptake, depuration, and radiation dose estimation in zebrafish exposed to radionuclides via aqueous or dietary routes

Understanding uptake and depuration of radionuclides in organisms is necessary to relate exposure to radiation dose and ultimately to biological effects. We investigated uptake and depuration of a mixture of radionuclides to link bioaccumulation with radiation dose in zebrafish, Danio rerio. Adult zebrafish were exposed to radionuclides (⁵⁴Mn, ⁶⁰Co, ⁶⁵Zn, ⁷⁵Se, ¹⁰⁹Cd, ^110mAg, ¹³⁴Cs and ²⁴¹Am) at tracer levels (< 200 Bq g⁻¹) for 14 d, either via water or diet. Radioactivity concentrations were measured in whole body and excised gonads of exposed fish during uptake (14 d) and depuration phases (47 d and 42 d for aqueous and dietary exposures respectively), and dose rates were modelled from activity concentrations in whole body and exposure medium (water or diet). After 14-day aqueous exposure, radionuclides were detected in decreasing activity concentrations: ⁷⁵Se > ⁶⁵Zn > ¹⁰⁹Cd > ^110mAg > ⁵⁴Mn > ⁶⁰Co > ²⁴¹Am > ¹³⁴Cs (range: 175-8 Bq g¹). After dietary exposure the order of radionuclide activity concentration in tissues (Bq g⁻¹) was: ⁶⁵Zn > ⁶⁰Co > ⁷⁵Se > ¹⁰⁹Cd > ^110mAg > ²⁴¹Am > ⁵⁴Mn > ¹³⁴Cs (range: 91-1 Bq g⁻¹). Aqueous exposure resulted in higher whole body activity concentrations for all radionuclides except ⁶⁰Co. Route of exposure did not appear to influence activity concentrations in gonads, except for ⁵⁴Mn, ⁶⁵Zn, and ⁷⁵Se, which had higher activity concentrations in gonads following aqueous exposure. Highest gonad activity concentrations (Bq g⁻¹) were for ⁷⁵Se (211), ¹⁰⁹Cd (142), and ⁶⁵Zn (117), and highest dose rates (μGy h⁻¹) were from ²⁴¹Am (aqueous, 1050; diet 242). This study links radionuclide bioaccumulation data obtained in laboratory experiments with radiation dose determined by application of a dosimetry modelling tool, an approach that will enable better linkages to be made between exposure, dose, and effects of radionuclides in organisms.     

Measurements of dermal uptake of nicotine directly from air and clothing

In this preliminary study, we have investigated whether dermal uptake of nicotine directly from air or indirectly from clothing can be a meaningful exposure pathway. Two participants wearing only shorts and a third participant wearing clean cotton clothes were exposed to environmental tobacco smoke (ETS), generated by mechanically “smoking” cigarettes, for three hours in a chamber while breathing clean air from head‐enveloping hoods. The average nicotine concentration (420 μg/m³) was comparable to the highest levels reported for smoking sections of pubs. Urine samples were collected immediately before exposure and 60 hour post‐exposure for bare‐skinned participants. For the clothed participant, post‐exposure urine samples were collected for 24 hour. This participant then entered the chamber for another three‐hour exposure wearing a hood and clothes, including a shirt that had been exposed for five days to elevated nicotine levels. The urine samples were analyzed for nicotine and two metabolites—cotinine and 3OH‐cotinine. Peak urinary cotinine and 3OH‐cotinine concentrations for the bare‐skinned participants were comparable to levels measured among non‐smokers in hospitality environments before smoking bans. The amount of dermally absorbed nicotine for each bare‐skinned participant was conservatively estimated at 570 μg, but may have been larger. For the participant wearing clean clothes, uptake was ~20 μg, and while wearing a shirt previously exposed to nicotine, uptake was ~80 μg. This study demonstrates meaningful dermal uptake of nicotine directly from air or from nicotine‐exposed clothes. The findings are especially relevant for children in homes with smoking or vaping.     

Evaluation of oxidative stress biomarkers in hepatocytes of grey mullet inhabiting natural and polluted estuaries

The aim of the study was to evaluate the impact of environmental contaminants on oxidative stress biomarkers in hepatocytes of Indian estuarine water grey mullet, Mugil cephalus collected from unpolluted Kovalam and polluted Ennore estuaries. Initially, a comparison was made between the general water chemistry and environmental pollutants like heavy metals to identify the ecotype of the estuaries. Biomarker responses and bioaccumulation of metals were determined along with histological studies of fish hepatocytes to assess contamination impact. Water chemistry data with higher temperature, salinity, pH, biochemical oxygen demand, chemical oxygen demand and low dissolved oxygen and environmental pollutants with higher metal concentration (p < 0.05) were observed at Ennore than Kovalam indicating its polluted environment. A significant increase (p < 0.05) in lipid and protein oxidation markers, decrease (p < 0.05) in thiol status and antioxidant enzyme activities were observed in the Ennore fish hepatocytes compared to Kovalam counterpart. Bioaccumulation of heavy metals was significantly higher (p < 0.05) in fish from Ennore. Hepatocytes from Ennore also featured extensive lipid-type vacuolation, increased size and membrane disruption. All the findings highlighted the value of oxidative stress biomarkers and membrane disruption as the sensitive parameters of environmental pollutant contamination and their importance in biomonitoring of aquatic ecosystems. This is also the first such attempt reported at the cellular level from South India stressing the importance of biomarkers in biomonitoring programmes using fish hepatocytes as the model system.     

Predicting blood lead levels from current and past environmental data in Europe

The present case study on lead in Europe illustrates the use of the Integrated Monitoring Framework Strategy to assess the health outcome of environmental pollution by evaluating the associations between lead in various environmental compartments (air, soil, dust, drinking water and diet) and lead concentrations in blood (B-Pb) for various age-related sub-populations. The case study was aimed to investigate whether environmental, exposure and biomonitoring data at general population level, covering all EU member states, could be integrated. Although blood lead has been monitored extensively in Europe, consistent datasets are not yet available. Data diverge with regard to objectives, regional scale, sampling years, gender, age groups and sample size.Significant correlations were found between B-Pb and the concentrations of Pb in air and diet. The significant decrease of the Pb in air over time from 0.31 μg/m³ (P95: 0.94; n = 98) prior to 1990 to 0.045 μg/m³ (P95: 0.11; n = 256) in 2007 (latest observations included) (Δ = − 85%) corresponds to a decline in B-Pb by 48% and 57% in adult women and adult men, respectively. For pre-school children a more shallow decline in B-Pb of 16% was calculated over the same period. Similarly, the reduction in Pb-dietary intake from on average 68.7 μg/d (P95: 161.6; n = 19) in 1978 to 35.7 μg/d (P95: 82.3; n = 33) in the years post 2000 (Δ = − 48%) is paralleled by a decline in B-Pb of 32, 33 and 19% in adult women, primary- and pre-school children, respectively. Insufficient data exist for other age groups to calculate statistically significant correlations.Although regression models have been derived to predict B-Pb for different sub-populations in Europe based on Pb concentrations in air and soil as well as dietary intake, it is concluded that the available data are insufficient to accurately predict actual and future simultaneous exposure to Pb from various environmental compartments, and as a consequence the health impact of Pb for various target populations at EU scale. At least due to data availability, air Pb remains the best predictor of B-Pb in the population. However, lead emission sources have largely been reduced and inhalation of lead in air is not causal to B-Pb levels. Therefore, there is a need of adequate data for Pb in soil and house dust, and in diet and drinking water as these are causal exposure sources with a longer Pb half-life than air. An extended and more harmonized surveillance system monitoring B-Pb, especially in children, is urgently required in order to identify, quantify and reduce still remaining sources of Pb exposure.