Spatiotemporal analysis and human exposure assessment on polycyclic aromatic hydrocarbons in indoor air,settled house dust,and diet: A review

This review summarizes the published literature on the presence of polycyclic aromatic hydrocarbons (PAH) in indoor air, settled house dust, and food, and highlights geographical and temporal trends in indoor PAH contamination. In both indoor air and dust, ΣPAH concentrations in North America have decreased over the past 30 years with a halving time of 6.7 ± 1.9 years in indoor air and 5.0 ± 2.3 years in indoor dust. In contrast, indoor PAH concentrations in Asia have remained steady. Concentrations of ΣPAH in indoor air are significantly (p < 0.01) higher in Asia than North America. In studies recording both vapor and particulate phases, the global average concentration in indoor air of ΣPAH excluding naphthalene is between 7 and 14,300 ng/m³. Over a similar period, the average ΣPAH concentration in house dust ranges between 127 to 115,817 ng/g. Indoor/outdoor ratios of atmospheric concentrations of ΣPAH have declined globally with a half-life of 6.3 ± 2.3 years. While indoor/outdoor ratios for benzo[a]pyrene toxicity equivalents (BaP_eq) declined in North America with a half-life of 12.2 ± 3.2 years, no significant decline was observed when data from all regions were considered. Comparison of the global database, revealed that I/O ratios for ΣPAH (average = 4.3 ± 1.3), exceeded significantly those of BaP_eq (average = 1.7 ± 0.4) in the same samples. The significant decline in global I/O ratios suggests that indoor sources of PAH have been controlled more effectively than outdoor sources. Moreover, the significantly higher I/O ratios for ΣPAH compared to BaP_eq, imply that indoor sources of PAH emit proportionally more of the less carcinogenic PAH than outdoor sources. Dietary exposure to PAH ranges from 137 to 55,000 ng/day. Definitive spatiotemporal trends in dietary exposure were precluded due to relatively small number of relevant studies. However, although reported in only one study, PAH concentrations in Chinese diets exceeded those in diet from other parts of the world, a pattern consistent with the spatial trends observed for concentrations of PAH in indoor air. Evaluation of human exposure to ΣPAH via inhalation, dust and diet ingestion, suggests that while intake via diet and inhalation exceeds that via dust ingestion; all three pathways contribute and merit continued assessment.     

DDTs in mothers' milk,placenta and hair,and health risk assessment for infants at two coastal and inland cities in China

This study is a one of the very few investigating the dichloro-diphenyl-trichloroethanes (DDTs) (summation of o,p′-DDE, p,p′-DDE, o,p′-DDD, p,p′-DDD, o,p′-DDT, and p,p′-DDT) in multiple human matrices in mothers' milk, placenta and hair collected from residents from two coastal cities: Guiyu (GY) and Taizhou (TZ) and one inland city: Lin'an (LA). TZ (milk: 360 ± 319 ng/g lipid wt.) showed significantly higher concentrations of DDTs than those from LA (milk: 190 ± 131 ng/g lipid wt.), whereas, concentrations of DDTs in GY (milk: 305 ± 109 ng/g lipid wt.) were in between TZ and LA. In addition, levels of DDTs in the human tissues from TZ (placenta: 122 ± 109 ng/g lipid wt.; hair: 79.9 ± 215 ng/g dry wt.) were significantly higher than those from Lin'an (placenta: 49.2 ± 30.2 ng/g lipid wt.; hair: 10.8 ± 7.09 ng/g dry wt.). The above concentrations of DDTs in milk exceeded the Codex Maximum Residue Limits/Extraneous Maximum Residue Limits for milk (20 ng/g lipid wt. whole milk), indicating that the human milk samples were grossly polluted. The present study revealed that human specimens collected from the coastal city (TZ) were more contaminated with inland one (LA), based on the levels of DDTs contained in samples which may be due to the higher dietary exposure to DDTs via consumption of contaminated seafood. The estimated daily intakes of DDTs by GY, TZ and LA infants were 1.69 ± 1.86, 1.48 ± 0.79, and 0.95 ± 0.73 μg/kg body wt./day, respectively which did not exceed 10 μg/kg body wt./day, the provisional tolerable daily intake proposed by the Food and Agriculture Organization/World Health Organization.     

Hydroxylated PCB metabolites (OH-PCBs) in archived serum from 1950–60s California mothers: A pilot study

We are studying participants selected from the Child Health and Development Studies (CHDS), a longitudinal birth cohort of over 20,000 California pregnancies between 1959 and 1967, for associations between maternal body burden of organochlorine contaminants and thyroid function. We designed a pilot study using 30 samples selected among samples with high and low PCB concentrations to evaluate the feasibility of measuring OH-PCBs in the larger study population. GC-ECD and GC-NCI/MS were used to determine PCBs and OH-PCBs as methyl derivatives, respectively. Maternal serum levels of Σ₁₁PCBs and Σ₈OH-PCB metabolites varied from 0.74 to 7.99 ng/mL wet wt. with a median of 3.05 ng/mL, and from 0.12 to 0.98 ng/mL wet wt. with a median of 0.39 ng/mL, respectively. Average concentrations of Σ₈OH-PCB metabolites in the high PCB group were significantly higher than those in the low PCB group (p < 0.05). The levels of OH-PCB metabolites were dependent on PCB levels (r = 0.58, p < 0.05) but approximately an order of magnitude lower (p < 0.05). The average ratio of Σ₈OH-PCBs to Σ₁₁PCBs was 0.14 ± 0.08. The primary metabolite was 4-OH-CB187 followed by 4-OH-CB107. Both of these metabolites interfere with the thyroid system in in vitro, animal, and human studies. OH-PCBs were detectable in all archived sera analyzed, supporting the feasibility to measure OH-PCB metabolites in the entire cohort.     

Chlorinated biphenyls and pesticides in migrating and resident seabirds from East and West Antarctica

The unhatched eggs of the following seabirds were analyzed to quantify PCBs, hexachlorobenzene (HCB), α-, β-, γ-, δ-hexachlorocyclohexanes (HCHs), o,p′ and p,p′ isomers of DDT, DDD and DDE: resident Adèlie (Pygoscelis adèliae, ADPE) and Emperor (Aptenodytes forsteri, EMPE) penguins, migrating snow petrel (Pagodroma nivea, SNPT) and South Polar skua (Catharacta maccormicki, SPSK) from the Ross Sea (East Antarctica); and migrating Brown skua (Catharacta antartica, BRSK) and resident ADPE from the Brainsfield Strait (West Antarctica). The general aims were to evaluate the contaminant accumulation in eggs of migrating and resident species in the two study areas, and to compare levels in penguins and skuas nesting in East and West Antarctica. PCB congener and HCH and DDT isomer profiles were also assessed. Comparisons were evaluated using seven PCB congeners (IUPAC nos. 28, 52, 101, 118 + 149, 138, 153, and 180), p,p′-DDE, ΣDDTs, and ΣHCHs. Higher contaminant concentrations were detected in migrating seabirds (South polar skua and brown skua) > sub-Antarctic species (snow petrel) > Antarctic species (penguins) from both the sampling sites, suggesting contamination events at lower latitudes for those birds migrating northward. HCHs showed the lowest concentrations in all species (from 0.03 ± 0.03 ng/g wet wt in SPSK to 1.81 ± 1.23 ng/g wet wt in ADPE from West Antarctica), and PCBs were the most abundant contaminants (from 4.34 ± 2.15 ng/g wet wt. in EMPE to 53.41 ± 19.61 ng/g wet wt. in brown skua). Among pesticides, it is relevant the detection of p,p′-DDT in Adèlie penguin from West Antarctica and in both species of skua; the detection of this pesticide can confirm its actual use in certain malaria-endemic countries from where it is transferred through the long range transport to the polar regions. Contaminants did not show any significant temporal trend during a ten year time span, from 1994/95 to 2004/05, in organisms collected in East Antarctica and they did not indicate any latitudinal gradient along the Ross Sea coasts.     

Tissue-specific accumulation of polybrominated diphenyl ethers (PBDEs) including Deca-BDE and hexabromocyclododecanes (HBCDs) in harbor seals from the northwest Atlantic

Polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) are widely used flame retardants that enter coastal waters from multiple sources and biomagnify in marine food webs. PBDEs have been detected at relatively high concentrations in harbor seals, apex predators in the northwest Atlantic. Whereas tri- to hexa-BDEs readily biomagnified from prey fishes to seal blubber, Deca-BDE (BDE-209) did not biomagnify in blubber. To explore tissue-specific differences in the accumulation/biomagnification of BFRs, we analyzed tri- to Deca-BDES in liver of 56 harbor seals (6 adult males, 50 pups), and compared hepatic concentrations and biomagnification potential with those in blubber. HBCDs were analyzed in seal liver and blubber to enable similar comparisons. Hepatic ΣPBDE (tri- to Octa-BDE) concentrations (range 35–19,547 ng/g lipid weight, lw) were similar to blubber concentrations, while α-HBCD levels in seal liver (range 2–279 ng/g lw) were significantly higher than levels in blubber. Tissue distribution of PBDEs and α-HBCD varied significantly by age and, surprisingly, by gender among the pups. Biomagnification of α-HBCD from fish to seal liver and blubber was negligible to low, implying that harbor seals can metabolize this persistent isomer. Similar to the patterns in blubber, tri- through hexa-BDEs were highly biomagnified from fish to seal liver. In contrast, BDE-209 concentrations in liver were up to five times higher than those in blubber, which is consistent with observations that BDE-209 migrates to perfused tissues such as the liver in biota. Although detection frequency was low, BDE-209 levels in seal liver were up to ten times higher than those in their prey fish, suggesting that the accumulation/biomagnification of Deca-BDE in marine food webs is tissue-specific. As BDE-209 is the dominant PBDE found in marine sediments, its biomagnification in marine ecosystems is of concern.     

Personal exposure to HBCDs and its degradation products via ingestion of indoor dust

Personal exposures via ingestion of indoor dust to α-, β-, and γ-hexabromocyclododecanes (HBCDs) and the degradation products (pentabromocyclododecenes (PBCDs) and tetrabromocyclododecadienes (TBCDs)) were estimated for 21 UK adults. Under an average dust ingestion scenario, personal exposures ranged from 4.5 to 1851 ng ΣHBCDs day^? 1; while the range under a high dust ingestion scenario was 11 to 4630 ng ΣHBCDs day^? 1. On average, personal exposure to ΣHBCDs via dust ingestion in this study was 35% α-, 11% β-, and 54% γ-HBCD. However, while exposure to β-HBCD (4–18% of ΣHBCDs) was relatively consistent with the proportion of this diastereomer in the HBCD commercial formulation; exposures to α- and γ-isomers (11–58% and 29–82% of ΣHBCDs respectively) showed substantial variation from the commercial formulation pattern. Personal exposures to ΣTBCDs (median = 0.2 ng day^? 1 under an average dust ingestion scenario) and ΣPBCDs (1.4 ng day^? 1) were significantly lower (p < 0.05) than for ΣHBCDs (48 ng day^? 1). Despite this, the exposure of one participant to ΣPBCDs exceeded the exposure to ΣHBCDs received by 85% of the other participants. On average, house dust provided the major contribution to personal exposure via dust ingestion to all target compounds due to the large time fraction spent in houses. In contrast, although participants spent less time in cars than in offices, car dust makes a higher average contribution (17%) to ΣHBCDs exposure than office dust (13%).     

Concentrations of chlorinated and brominated contaminants and their metabolites in serum of harbour seals and harbour porpoises

Harbour seals (Phoca vitulina) and harbour porpoises (Phocoena phocoena) are top predators in the North Sea and consequently accumulate a variety of pollutants in their tissues. Concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and their hydroxylated metabolites (HO-PCBs and HO-PBDEs) were measured in serum of wild harbour seals (n = 47) and captive harbour porpoises (n = 21). Both species exhibit long life spans and do not have extreme situations, such as complete fasting during periods of lactation, in their annual cycles. For PCBs, concentrations in adult males were slightly higher than in juveniles and lowest in juvenile females. For PBDEs, juveniles have higher levels than adult males and females, probably as a consequence of lactational transfer. However, differences between these age–gender groups were not statistical significant, indicating that individual variation was limited within each species, even without knowing the feeding status of the animals. Body condition, particularly emaciation, has a major influence on the levels of chlorinated and brominated contaminants in serum. Profiles of PCBs were CB 153 > CB 138 > CB 187 > CB 180 and CB 153 > CB 138 > CB 149 > CB 187 > CB 180 for harbour seals and porpoises respectively. For PBDEs, BDE 47 was the predominant congener followed by BDE 100 and 99 in both species. In harbour seals, concentrations of sum PCBs (median: 39,200 pg/ml) were more than 200 times higher than levels of sum PBDEs (median: 130 pg/ml) and almost 10 times higher than concentrations of sum HO-PCBs (4350 pg/ml). In harbour porpoises, concentrations of sum PCBs (median: 24,300 pg/ml) were about 20 times higher than concentrations of PBDEs (median: 1300 pg/ml). HO-PCBs were detected in only 4 harbour porpoises and this at very low concentrations. Naturally-produced MeO-PBDEs were only found in harbour porpoises at concentrations ranging from 120 to 810 pg/ml. HO-PBDEs were not found in any species. In general, harbour seals accumulate less compounds and have mostly lower concentrations than harbour porpoises possibly as a result of a better developed metabolism.     

The bioavailability of selenium and risk assessment for human selenium poisoning in high-Se areas,China

Enshi prefecture of Hubei Province is well known for human selenium (Se) poisoning in the early 1960s in China. Sporadic cases of Se poisoning in livestocks are still being found. In this study, Se levels in water, cropland soils and various crops from high-Se areas of Enshi were measured to investigate the distribution and bioavailability of Se in the environments, as well as probable daily intake (PDI) of Se for local residents. The total Se in surface water ranged from 2.0 to 519.3 μg/L with a geometric mean of 46.0 ± 127.8 μg/L (n = 48), 70.5–99.5% of which was present in the form of Se(VI). The soil Se concentration varied from 2.89 to 87.3 μg/g with a geometric mean of 9.36 ± 18.6 μg/g (n = 45), and most of Se was associated with organic matter (OM-Se). The total Se in rice, corn, and vegetable samples were 2.11 ± 2.87 μg/g (n = 21), 3.76 ± 11.6 μg/g (n = 16), and 2.09 ± 3.38 μg/g (n = 25), respectively. Stream water Se is likely leached from carbonaceous shale and mine wastes, leading to Se accumulation in paddy soils. OM-Se may play an important role in Se uptake by rice plant in high-Se area of Enshi.The PDI of Se is approximately 2144 μg/day, and Se concentration in blood is estimated at about 3248 μg/L, posing a potential chronic Se poisoning risk to local residents. Cereal consumption (48.5%) makes a great contribution to human daily Se intake, followed by vegetables (36.6%), meats (8.5%), and drinking water (6.4%). However, when assessing health risk on human in high-Se areas, the contribution of drinking water to daily Se intake cannot be ignored due to high Se content and dominant Se(VI) species. Local inhabitants should be advised not to grow crops in high-Se lands or irrigate using high-Se water. If possible, they should drink pipe water and consume foods mixed with those from outside the high-Se areas.     

Polybrominated diphenyl ethers (PBDEs) in human samples of mother–newborn pairs in South China and their placental transfer characteristics

There are limited data concerning the placenta transfer characteristics and accumulation of polybrominated diphenyl ethers (PBDEs) in infants. However, PBDEs received increasing health concerns due to their endocrine disrupt and neurodevelopment toxicity effects. The present study assessed the accumulation of PBDEs in 30 paired placenta, breast milk, fetal cord blood, and neonatal urine samples collected from five major cities of the South China. The age of mothers ranged from 21 to 39 (mean 27.6 ± 4.56). The ∑ PBDE concentrations were 15.8 ± 9.88 ng g^− 1 lipid in placenta, 13.2 ± 7.64 ng g^− 1 lipid in breast milk, 16.5 ± 19.5 ng g^− 1 lipid in fetal cord blood, and 1.80 ± 1.99 ng ml^− 1 in neonatal urine. BDE-47 was the predominant congener in all types of human sample. Octa-BDEs such as BDE-196/-197 were detected highly in placenta and cord blood while moderately in breast milk and neonatal urine. Significant (p < 0.01) correlations were observed for both total and most individual PBDEs in cord blood–maternal placenta and breast milk–urine paired individual samples. The extent of placental transfer of higher brominated BDEs such as BDE-196/-197 was greater than that of BDE-47. The estimated daily intake (EDI) analysis for breast-fed infants revealed that newborns in these areas were exposed to relatively high levels of PBDEs via breast milk. Our study not only provided systematic fundamental data for PBDE distribution but also revealed the placenta transfer characteristics of PBDE congeners in South China.     

Novel brominated flame retardants in food composites and human milk from the Chinese Total Diet Study in 2011: Concentrations and a dietary exposure assessment

On the basis of the fifth Chinese total diet study (TDS) performed in 2011, the dietary exposure of the Chinese population to novel brominated flame retardants (NBFRs) was assessed. Six NBFRs were determined in 80 composite samples from four animal origin food groups and 29 pooled human milk samples. Based on gas chromatography-negative chemical ionization mass spectrometry (GC-NCI/MS) analysis, the levels of the total NBFRs ranged from < LOD to 70.2 ng/g lipid weight (lw) in food composites and from 2.48 to 23.9 ng/g lw in human milk samples. Decabromodiphenyl ethane (DBDPE), with mean levels of 9.03 ng/g lw in food composites and 8.06 ng/g lw in human milk, was the most abundant compound in the total NBFRs. No obvious spatial distribution patterns in China were observed in food samples or human milk. The average estimated daily intake (EDI) of total NBFRs via food consumption for a “standard Chinese man” was 4.77 ng/kg bodyweight (bw)/day, with a range of 0.681 to 18.9 ng/kg bw/day. Meat and meat products were the main dietary source of NBFRs, although levels of NBFRs in aquatic food were found to be the highest among the four food groups. The average EDI of total NBFRs for nursing infants was 38.4 ng/kg bw/day, with a range of 17.4 to 113 ng/kg bw/day, which was approximately eight-fold higher than the EDI for adults, suggesting the heavy body burden of NBFRs on nursing infants. The levels and EDI of DBDPE in the present study were similar to or higher than those of legacy BFRs (i.e., PBDEs and HBCD) in the TDS 2007, indicating that DBDPE, as a main alternative to PBDEs, might have become the primary BFR used in China.     

Polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) in breast milk from Zhejiang,China

Breast milk samples (n = 74) from the general maternal population of Zhejiang province were analyzed for polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs). Samples were divided into urban and rural groups. Mean ∑PCDD/F, ∑PCB and ∑PBDE concentrations were 71.4 ± 40.8, 42774 ± 27841 and 2679 ± 944 pg g^− 1 lipid in the urban group and 38.6 ± 38.1, 26546 ± 11375 and 2731 ± 1093 pg g^− 1 lipid in the rural group, respectively. WHO-TEQ concentrations for dioxin-like PCBs and PCDD/Fs were 2.66 ± 1.43 and 3.90 ± 2.60 pg g^− 1 lipid in the urban group and 1.83 ± 0.93 and 2.27 ± 1.55 pg g^− 1 lipid in the rural group, respectively. Congener profiles for these pollutants were compared between human samples (adipose tissue and breast milk) and foodstuffs (seafood, hen eggs, and freshwater fish). Similar PCB and PCDD/F congener patterns were observed, suggesting that dietary intake is a significant source for human exposure to PCBs and PCDD/Fs. However, much lower PBDE congener levels were detected in breast milk than in foodstuffs, which implies that pathways other than dietary intake may also account for human exposure to PBDEs.     

Can starling eggs be useful as a biomonitoring tool to study organohalogenated contaminants on a worldwide scale?

Large-scale international monitoring studies are important to assess emission patterns and environmental distributions of organohalogenated contaminants (OHCs) on a worldwide scale. In this study, the presence of OHCs was investigated on three continents (Europe, North America and Australasia), using eggs of starlings (Sturnus vulgaris and Sturnus unicolor) to assess their suitability for large-scale monitoring studies. To the best of our knowledge, this is the first study using bird eggs of the same species as a biomonitor for OHCs on an intercontinental scale. We found significant differences in OHC concentrations of the eggs among sampling locations, except for hexachlorocyclohexanes (HCHs). Mean concentrations of sum polychlorinated biphenyls (PCBs) in eggs ranged from 78 ± 26 ng/g lipid weight (lw) in Australia to 2900 ± 1300 ng/g lw in the United States. The PCB profile was dominated by CB 153 and CB 138 in all locations, except for New Zealand, where the contribution of CB 95, CB 101 and CB 149 was also high. The highest mean sum polybrominated diphenyl ether (PBDE) concentrations were found in Canada (4400 ± 830 ng/g lw), while the lowest mean PBDE concentrations were measured in Spain (3.7 ± 0.1 ng/g lw). The PBDE profile in starling eggs was dominated by BDE 47 and BDE 99 in all countries, but in Belgium, the higher brominated PBDEs had a higher contribution compared to other countries. For the organochlorine pesticides (OCPs), dichlorodiphenyltrichloroethanes (DDTs) ranged from 110 ± 16 ng/g lw in France to 17,000 ± 3400 ng/g lw in New Zealand, while HCHs and hexachlorobenzene were generally in low concentrations in all sampling locations. Chlordanes were remarkably high in eggs from the United States (2500 ± 1300 ng/g lw). The OCP profile in all countries was largely dominated by p,p′-DDE. In general, the worldwide trends we observed in starling eggs were in accordance with the literature on human and environmental OHC data, which suggests that there is potential for using starling eggs as a biomonitoring tool on a large geographical scale.     

Blood pressure changes in association with black carbon exposure in a panel of healthy adults are independent of retinal microcirculation

Exposure to ambient particulate matter and elevated blood pressure are risk factors for cardiovascular morbidity and mortality. Microvascular changes might be an important pathway in explaining the association between air pollution and blood pressure. The objective of the study was to evaluate the role of the retinal microcirculation in the association between black carbon (BC) exposure and blood pressure.We estimated subchronic BC exposure based on 1-week personal measurements (μ-Aethalometer, AethLabs) in 55 healthy nurses. Blood pressure and retinal microvasculature were measured on four different days (range: 2–4) during this week.Subchronic BC exposure averaged (± SD) 1334 ± 631 ng/m³ and ranged from 338 ng/m³ to 3889 ng/m³. An increased exposure of 631 ng/m³ BC was associated with a 2.77 mm Hg (95% CI: 0.39 to 5.15, p = 0.027) increase in systolic blood pressure, a 2.35 mm Hg (95% CI: 0.52 to 4.19, p = 0.016) increase in diastolic blood pressure and with 5.65 μm (95% CI: 1.33 to 9.96, p = 0.014) increase in central retinal venular equivalent. Mediation analysis failed to reveal an effect of retinal microvasculature in the association between blood pressure and subchronic BC exposure.In conclusion, we found a positive association between blood pressure and subchronic black carbon exposure in healthy adults. This finding adds evidence to the association between black carbon exposure and cardiovascular health effects, with elevated blood pressure as a plausible intermediate effector. Our results suggest that the changes in a person's blood pressure as a result of subchronic black carbon exposure operate independently of the retinal microcirculation.     

The bioaccessibility of polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) in cooked plant and animal origin foods

In this study, we compared the effect of boiling and frying food preparation methods in determining the bioaccessibility of polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) in rice, cabbage, milk powder, eggs, beef, and fresh water fish. We then used these data to calculate a toxic equivalent (TEQ) for risk assessment and compared it to published values that did not account for bioaccessibility.When the foods were prepared by boiling, the mean bioaccessibility (%) in rice (PCBs: 16.5 ± 1.0, PCDD/Fs: 4.9 ± 0.3) and cabbage (PCBs: 4.2 ± 0.9, PCDD/Fs: 1.9 ± 0.7) were lower than in animal origin foods (beef, PCBs: 49.0 ± 3.3, PCDD/Fs: 7.8 ± 0.9; egg, PCBs: 29.7 ± 3.1, PCDD/Fs: 8.6 ± 1.3; fish, PCBs: 26.9 ± 2.5, PCDD/Fs: 7.9 ± 1.3; milk powder, PCBs: 72.3 ± 1.6, PCDD/Fs: 28.4 ± 1.2).When fried in cooking oil, the bioaccessibilities of all analytes in all foods increased, but the increase in plant based foods (rice, PCBs: 3.4 ×, PCDD/Fs: 3.6 ×; cabbage, PCBs: 10.3 ×, PCDD/Fs: 7.9 ×) was greater than that of animal origin foods (beef, PCBs: 1.6 ×, PCDD/Fs: 3.4 ×; egg, PCBs: 2.1 ×, PCDD/Fs: 1.8 ×; fish, PCBs: 2.8, PCDD/Fs: 3.2 ×).Comparison of PCBs/PCDD/Fs bioaccessibility in rice and cabbage showed that bioaccessibility was greater in the low fat, high carbohydrate/protein content food (rice) than in the low carbohydrate/protein, low fat content food (cabbage), regardless of the method used to prepare the food.Adjusting for bioaccessibility reduced the gross estimated daily intake (EDI) of 112 pg WHO-TEQ/day, by 88% and 63% respectively for foods prepared by boiling and frying.Our results indicate that: 1) The method used for cooking is an important determinant of PCBs/PCDD/Fs bioaccessibility, especially for plant origin foods, 2) there might be a joint fat, carbohydrate and protein effect that influences the bioaccessibilities of PCBs/PCDD/Fs in foods, and 3) use of bioaccessibility estimates would reduce the uncertainty in TEQ calculations.     

Human dietary intake of organohalogen contaminants at e-waste recycling sites in Eastern China

This study reports concentrations and human dietary intake of hexabromocyclododecanes (HBCDs), polychlorinated biphenyls (PCBs) as well as selected “novel” brominated flame retardants (NBFRs) and organochlorine pesticides, in ten staple food categories. Samples were sourced from areas in Taizhou City, eastern China, where rudimentary recycling and disposal of e-waste is commonplace, as well as from nearby non-e-waste impacted control areas. In most instances, concentrations in foods from e-waste recycling areas exceeded those from control locations. Concentrations of 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB) and bis-(2-ethylhexyl)-3,4,5,6-tetrabromophthalate (BEH-TBP) in samples from e-waste sites were 3.09–62.2 ng/g and 0.81–16.3 ng/g lipid weight (lw), respectively; exceeding consistently those in foods acquired from control sites by an order of magnitude in many cases. In contrast, while concentrations of HBCD in some foods from e-waste impacted areas exceed those from control locations; concentrations in pork, shrimp, and duck liver are higher in control samples. This highlights the potential significance of non-e-waste sources of HBCD (e.g. building insulation foam) in our study areas. While concentrations of DDT in all foods examined except pork were higher in e-waste impacted samples than controls; our exposure estimates were well below the provisional tolerable daily intake of 0.01 mg/kg bw/day derived by the Joint FAO/WHO Meeting on Pesticide Residues. Concentrations of ΣPCBs resulted in exposures (650 and 2340 ng/kg bw/day for adults and children respectively) that exceed substantially the Minimal Risk Levels (MRLs) for ΣPCBs of 20 ng/kg bw/day derived by the Agency for Toxic Substances & Disease Registry. Moreover, when expressed in terms of dioxin-like toxicity equivalency based on the four dioxin-like PCBs monitored in this study (DL-PCBs) (PCB-105, 118, 156, and 167); concentrations in e-waste impacted foods exceed limits set by the European Union in 6 of the 8 food groups studied and result in dietary exposures for children (10.2 pg TEQ/kg bw/day) that exceed the WHO tolerable daily intake of 1–4 pg TEQ/kg bw/day.     

Associations between polycyclic aromatic hydrocarbon (PAH) exposure and oxidative stress in people living near e-waste recycling facilities in China

Emission of polycyclic aromatic hydrocarbons (PAHs) from e-waste recycling activities in China is known. However, little is known on the association between PAH exposure and oxidative damage to DNA and lipid content in people living near e-waste dismantling sites. In this study, ten hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and two biomarkers [8-hydroxy-2′-deoxyguanosine (8-OHdG) and malondialdehyde (MDA)] of oxidative stress were investigated in urine samples collected from people living in and around e-waste dismantling facilities, and in reference population from rural and urban areas in China. The urinary levels of ∑₁₀OH-PAHs determined in e-waste recycling area (GM: 25.4 μg/g Cre) were significantly higher (p < 0.05) than those found in both rural (11.7 μg/g Cre) and urban (10.9 μg/g Cre) reference areas. The occupationally exposed e-waste workers (36.6 μg/g Cre) showed significantly higher (p < 0.01) urinary Σ₁₀OH-PAHs concentrations than non-occupationally exposed people (23.2 μg/g Cre) living in the e-waste recycling site. The differences in urinary Σ₁₀OH-PAHs levels between smokers (23.4 μg/g Cre) and non-smokers (24.7 μg/g Cre) were not significant (p > 0.05) in e-waste dismantling sites, while these differences were significant (p < 0.05) in rural and urban reference areas; this indicated that smoking is not associated with elevated levels of PAH exposure in e-waste dismantling site. Furthermore, we found that urinary concentrations of Σ₁₀OH-PAHs and individual OH-PAHs were significantly associated with elevated 8-OHdG, in samples collected from e-waste dismantling site; the levels of urinary 1-hydroxypyrene (1-PYR) (r = 0.284, p < 0.01) was significantly positively associated with MDA. Our results indicate that the exposure to PAHs at the e-waste dismantling site may have an effect on oxidative damage to DNA among selected participants, but this needs to be validated in large studies.     

Emerging and historical brominated flame retardants in peregrine falcon (Falco peregrinus) eggs from Canada and Spain

Comparisons of brominated flame retardants (BFRs) in the eggs of peregrine falcons (Falco peregrinus) recently collected (2003–2007), are made between Canada (N = 12) and Spain (N = 13). Overall, concentrations of sum (Σ) polybrominated diphenyl ethers (PBDEs; 16 di-deca-BDE congeners) exceeded Σhexabromocyclododecane (HBCD) and were an order of magnitude higher than 2,2′4,4′,5,5′-hexabromobiphenyl (BB-153) > hexachlorocyclopentenyl-dibromocyclooctane (HCBDCO) > 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) > decabromodiphenylethane (DBDPE) > octabromotrimethylphenyllindane (OBIND) > hexabromobenzene (HBB) > bis(2-ethyl-1hexyl)tetrabromophthalate (BEHTBP). This is the first report of detectable HBCDCO and BEHTBP concentrations in biota, and the highest in ovo concentration of ∑ HBCD (14,617 ng/g lw; Montreal, Canada) to date. There were significantly greater egg concentrations of BB-153, ΣHBCD, and ΣPBDE including BDE-153, -99, -100 and -183, in Canadian than Spanish peregrines with a terrestrial diet. HBB, BTBPE, and OBIND were detected in eggs from both countries, but only Canadian peregrine eggs had detectable levels of HCDBCO (25%) and DBDPE (N = 1). The in ovo PBDE congener profile was dominated by BDE-153 > BDE-99 > BDE-47 > BDE-183 > BDE-100 > BDE-209, with the isomeric HBCD pattern being α-HBCD > γ-HBCD (β-HBCD undetected). The Canadian peregrine eggs had lower enantiomeric HBCD values consistent with their higher fractions of (−) α-HBCD, suggesting selective enantiomeric enrichment or that the (+) α-isomer is more readily metabolized and so deposited in the egg through maternal transfer. Continental differences in egg burdens of peregrines are discussed relative to BFR usage patterns and exposure of peregrines on their breeding grounds.     

Occurrence of parabens in foodstuffs from China and its implications for human dietary exposure

Parabens are alkyl esters of p-hydroxybenzoic acid and are used as antimicrobial preservatives in a range of consumer products, including cosmetics, pharmaceuticals, and foodstuffs. Despite their widespread use, prior to this study, paraben concentrations in foodstuffs from China and human dietary exposure to these chemicals have been unknown. In this study, concentrations of six parabens were determined in 13 categories of food samples (n = 282), including cereals and cereal products, meat, fish and seafood, eggs, dairy products, bean products, fruits, vegetables, cookies, beverages, cooking oils, condiments, and others, collected from nine cities in China. Almost all (detection rate: 99%) food samples contained at least one of the parabens analyzed, and the total concentrations (ΣParabens; sum of six parabens) ranged from below limit of quantification (LOQ) to 2530 ng/g fresh weight, with an overall mean value of 39.3 ng/g. Methyl paraben (MeP), ethyl paraben (EtP), and propyl paraben (PrP) were the major paraben analogs found in foodstuffs, and these compounds accounted for 59%, 24%, and 10%, respectively, of ΣParaben concentrations. Although the mean concentrations of ΣParabens varied among different categories of food items (from 0.839 ng/g in beverages to 100 ng/g in vegetables), the concentrations were not statistically significant among the 13 food categories, including canned foodstuffs. Estimated daily intake (EDI) of parabens was based on the measured concentrations in foods and the corresponding daily food ingestion rates. The mean and 95th percentile values for EDI were 1010 and 3040 ng/kg body weight (bw)/day for adult men and 1060 and 3170 ng/kg bw/day for adult women, respectively.     

Pyrethroids: A new threat to marine mammals?

The present study constitutes the first investigation to demonstrate pyrethroid bioaccumulation in marine mammals, despite the assumption that these insecticides are converted to non-toxic metabolites by hydrolysis in mammals. Twelve pyrethroids were determined in liver samples from 23 male franciscana dolphins from Brazil. The median concentration values for total pyrethroids were 7.04 and 68.4 ng/g lw in adults and calves, respectively. Permethrin was the predominant compound, contributing for 55% of the total pyrethroids. Results showed a distinct metabolic balance of pyrethroids through dolphin life. High loads are received at the beginning of their lives and, when they reach sexual maturity, these mammals seem to degrade/metabolize pyrethroids. Maternal transfer of these compounds was also evaluated through the analysis of breast milk and placenta samples. Pyrethroids were detected in both matrices, with values between 2.53–4.77 ng/g lw and 331–1812 ng/g lw, respectively. Therefore, for the first time, a study shows mother-to-calf transfer of pyrethroids by both gestational and lactation pathways in dolphins.     

Within-room and within-building temporal and spatial variations in concentrations of polybrominated diphenyl ethers (PBDEs) in indoor dust

Within-house and within-room spatial temporal variability in PBDE contamination of indoor dust may influence substantially the reliability of human exposure assessments based on single point samples, but have hitherto been little studied. This paper reports concentrations of PBDEs 17, 28, 47, 49, 66, 85, 99, 100, 153, and 154 in indoor dust samples (n = 112) from two houses in Birmingham, UK. To evaluate within-house spatial variability, four separate rooms were sampled in house 1 and two separate rooms sampled in house 2. Up to four different 1 m² areas in the same room were sampled to evaluate within-room spatial variability, and for all studied areas, samples were taken for eight consecutive months to evaluate temporal and seasonal variability. Concentrations of ΣPBDEs in individual samples from house 1 varied between 21 and 280 ng g^− 1; while the range of concentrations in house 2 was 20–1000 ng g^− 1. This indicates that where and when a sample is taken in a house can influence substantially the contamination detected. In one room, concentrations of PBDEs in an area located close to putative PBDE sources exceeded substantially those in an area 2 m away, with marked differences also observed between two areas in another room. Substantial within-room spatial differences in PBDE concentrations were not discernible in the other rooms studied. Concentrations of PBDEs in the majority of rooms within the same houses were not markedly different between rooms. Nevertheless, large differences were observed between PBDE concentrations detected in two rooms in the same house in both houses studied. In one instance, this is hypothesised to be attributable to the presence of a carpet in one room and bare wooden floor in another, but firm conclusions cannot be drawn. Within-room temporal (month-to-month) variability was substantial (relative standard deviations for ΣPBDEs = 15–200%). In some rooms, the introduction and removal of putative sources like a TV and a bed, appeared to exert a discernible influence on PBDE concentrations. PBDE concentrations in spring and summer were not markedly different from those observed in autumn and winter. Possible dilution of PBDE concentrations in dust at higher dust loadings (g dust per m² floor surface) was investigated in a small number of rooms, but no firm evidence of such dilution was evident.