Critical review on disposition of chlorinated paraffins in animals and humans.

Even though the chlorinated paraffins (CPs) have been on the environmental pollution agenda throughout the last 50 years it is a class of chemicals that only now is discussed in terms of an emerging issue with extensive annual publication rates. Major reviews on CPs have been produced, but a deeper understanding of the chemical fate of CPs, including formation of metabolites in animals and humans, is still missing. Thus, the present review aims to critically compile our present knowledge on the disposition, i.e. Adsorption, Disposition, Metabolism, and Excretion (ADME) of CPs in biota and to identify research needs. We conclude that CPs could be effectively absorbed from the gastro-intestinal tract (GI) tract, and probably also from the lungs, and transported to various organs. A biphasic elimination is suggested, with a rapid initial phase followed by a terminal phase, the latter (e.g., fat tissues) covering half-lives of weeks and months. CPs are metabolized in the liver and excreted mainly via the bile and faeces, and the metabolic rate and type of metabolites are dependent on chlorine content and chain length. Results that strengthen CP metabolism are in vivo findings of phase II metabolites in bile, and CP degradation to carbon fragments in experimental animals. Still the metabolic transformations of CPs are poorly studied, and no metabolic scheme has yet been presented. Further, toxicokinetic mass balance calculations suggest that a large part of a given dose (not found as parent compound) is transformation products of CPs, and in vitro metabolism studies present numerous CP metabolites (e.g., chloroalkenes, chlorinated ketones, aldehydes, and carboxylic acids).

Chlorinated paraffins leaking from hand blenders can lead to significant human exposures.

BACKGROUND: Chlorinated paraffins (CPs, polychlorinated n-alkanes) are versatile, high-production-volume chemicals. A previous study indicated that hand blenders leak CPs into prepared food. OBJECTIVES: (1) to estimate exposure to CPs from hand blender use compared to background CP exposure from diet; (2) to assess the risk from human dietary exposure to CPs from hand blender use; (3) to investigate how hand blenders leak out CPs. METHODS: CPs were analyzed in food market baskets, in cooking oil/water samples (1g oil/100mL water) mixed using 16 different hand blenders, and in dismantled components of the hand blenders. RESULTS: Dietary intake of CPs from food market baskets was calculated to be 4.6µg/day per capita for Swedish adults. Total CP amounts in oil/water leakage samples ranged from <0.09 to 120µg using the hand blenders once. CP leakage showed no decreasing levels after 20 times of hand blender usage. CP profiles in the leakage samples matched those of self-lubricating bearings and/or polymer components disassembled from the hand blenders. CONCLUSIONS: Usage of 75% of the hand blenders tested will lead to increased human exposure to CPs. The intake of CPs for Swedish adults by using hand blenders once a day can raise their daily dietary intake by a factor of up to 26. The 95th percentile intake of CPs via using the hand blenders once a day exceeded the TDI for Swedish infants with a body weight <7.2kg. CP leakage came from blender components which contain CPs. The leakage may last several hundred times of hand blender use.

Dietary intake of phosphorus flame retardants (PFRs) using Swedish food market basket estimations.

The occurrence of eight phosphorus flame retardants (PFRs) was investigated in 53 composite food samples from 12 food categories, collected in 2015 for a Swedish food market basket study. 2-ethylhexyl diphenyl phosphate (EHDPHP), detected in most food categories, had the highest median concentrations (9 ng/g ww, pastries). It was followed by triphenyl phosphate (TPHP) (2.6 ng/g ww, fats/oils), tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) (1.0 ng/g ww, fats/oils), tris(2-chloroethyl) phosphate (TCEP) (1.0 ng/g ww, fats/oils), and tris(1-chloro-2-propyl) phosphate (TCIPP) (0.80 ng/g ww, pastries). Tris(2-ethylhexyl) phosphate (TEHP), tri-n-butyl phosphate (TNBP), and tris(2-butoxyethyl) phosphate (TBOEP) were not detected in the analyzed food samples. The major contributor to the total dietary intake was EHDPHP (57%), and the food categories which contributed the most to the total intake of PFRs were processed food, such as cereals (26%), pastries (10%), sugar/sweets (11%), and beverages (17%). The daily per capita intake of PFRs (TCEP, TPHP, EHDPHP, TDCIPP, TCIPP) from food ranged from 406 to 3266 ng/day (or 6-49 ng/kg bw/day), lower than the health-based reference doses. This is the first study reporting PFR intakes from other food categories than fish (here accounting for 3%). Our results suggest that the estimated human dietary exposure to PFRs may be equally important to the ingestion of dust.

Serum levels of brominated flame retardants (BFRs: PBDE, HBCD) and influence of dietary factors in a population-based study on Swedish adults.

The aim of this study was to investigate associations between serum concentrations of brominated flame retardants and personal characteristics, including diet, in adults participating in a population-based study in Sweden 2010-11. Moreover, observed concentrations were used in a health risk assessment, using published health-based reference values. Serum samples of 170 adult individuals of both sexes were analyzed for 10 PBDE congeners and HBCD by GC-MS. When including concentrations between LOD and LOQ, highest median serum concentration was observed for BDE-153 (1.2 ng/g serum lipid), followed by BDE-209 (0.95 ng/g lipid), BDE-47 (0.49 ng/g lipid) and BDE-100 (0.21 ng/g lipid). Median concentration of HBCD was 0.10 ng/g lipid. A few markedly elevated concentrations of BDE-209, HBCD (77-78 ng/g lipid) and BDE-47 (44 ng/g lipid) were observed. The only statistical significant findings were higher BDE-153 concentrations in men than in women, and positive associations between serum BDE-153 concentrations and consumption of fish (total), beef, mutton and poultry. PBDE concentrations were in accordance with concentrations reported in other European countries but generally lower than those found in North America. Median PBDE serum concentrations observed in adults from Sweden suggest sufficient health protection, when compared with published health-based reference values, although some outliers with high serum concentrations had lower safety margins.

Diverging temporal trends of human exposure to bisphenols and plastizisers, such as phthalates, caused by substitution of legacy EDCs?

Phthalates and phenolic substances were investigated in urine samples from first-time mothers in Uppsala, Sweden, collected between 2009 and 2014. These substances have a comparably fast metabolism and urinary metabolites are predominantly analysed. The main aim was to investigate if measures to decrease production and use of certain phthalates and bisphenol A (BPA) have resulted in decreased human exposure, and to determine if exposures to replacement chemicals have increased. Temporal trends were evaluated for metabolites (n=13) of seven phthalates, a phthalate replacer, four different bisphenols, triclosan, one organophosphate-based flame retardant, and for two pesticides. The results showed downward trends of several phthalates which are in the process of being regulated and phased out. Concomitantly, an increasing trend was seen for a metabolite of the phthalate replacer Di-iso-nonylcyclohexane 1,2-dicarboxylate (DiNCH). Bisphenol A (BPA) showed a downward trend, whereas bisphenol F, identified as one of the substitutes for BPA, showed an increasing trend. The decreasing trend of triclosan is likely due to declining use within the EU. Temporal trend studies of urine samples make it possible to investigate human exposure to rapidly metabolised substances and study how measures taken to regulate and replace problematic chemicals affect human exposure.

Maternal body burdens of PCDD/Fs and PBDEs are associated with maternal serum levels of thyroid hormones in early pregnancy: a cross-sectional study.

BACKGROUND: Thyroid hormones (THs) regulate many biological functions in the human body and are essential for normal brain development. Epidemiological studies have observed diverging associations between halogenated persistent organic pollutant (POP) exposure and concentrations of THs in pregnant women and their infants. We investigated whether background exposure to polybrominated diphenyl ethers (PBDEs) is related to TH status in a Swedish population of pregnant women and their infants. Furthermore, we examined associations between polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) and TH status in early pregnancy as an extension of an earlier study focusing on late pregnancy TH status. METHODS: Free thyroxine (T4), total triiodo-thyronine (T3) and thyroid stimulating hormone (TSH) were analysed in serum from first-time mothers (N = 220-281) in the first and third trimester, and in infants (N = 115-150) 3 weeks and 3 months after delivery. Antibodies to thyroid peroxidase (anti-TPO) (N = 260) were measured in maternal third trimester serum. Maternal body burdens of PCBs (N = 281) were estimated from serum lipid PCB concentrations in late pregnancy, and PCDD/F (N = 97) and PBDE (N = 186) body burdens were estimated from concentrations in mother's milk lipids 3 weeks after delivery. Linear regression models allowed for covariate adjustment of the associations between ln-transformed POP body burdens and concentrations of TH and anti-TPO. RESULTS: Maternal body burden of BDE-153 was inversely associated with first trimester total T3, otherwise no associations between PBDEs and first and second trimester THs were observed. No associations were found between maternal PBDE body burdens and infant THs. Maternal body burden of PCDD/Fs were inversely associated with first trimester total T3. No associations were observed between PCBs and first trimester THs. Third trimester anti-TPO was not associated with maternal PCBs, PCDD/Fs and PBDEs. CONCLUSIONS: Our results suggest that maternal PCDD/F and BDE-153 body burdens influence maternal TH status in early pregnancy, which is a critical period when maternal TH status influences fetal development.

Time-dependent depletion of nitrite in pork/beef and chicken meat products and its effect on nitrite intake estimation.

The food additive nitrite (E249, E250) is commonly used in meat curing as a food preservation method. Because of potential negative health effects of nitrite, its use is strictly regulated. In an earlier study we have shown that the calculated intake of nitrite in children can exceed the acceptable daily intake (ADI) when conversion from dietary nitrate to nitrite is included. This study examined time-dependent changes in nitrite levels in four Swedish meat products frequently eaten by children: pork/beef sausage, liver paté and two types of chicken sausage, and how the production process, storage and also boiling (e.g., simmering in salted water) and frying affect the initial added nitrite level. The results showed a steep decrease in nitrite level between the point of addition to the product and the first sampling of the product 24 h later. After this time, residual nitrite levels continued to decrease, but much more slowly, until the recommended use-by date. Interestingly, this continuing decrease in nitrite was much smaller in the chicken products than in the pork/beef products. In a pilot study on pork/beef sausage, we found no effects of boiling on residual nitrite levels, but frying decreased nitrite levels by 50%. In scenarios of time-dependent depletion of nitrite using the data obtained for sausages to represent all cured meat products and including conversion from dietary nitrate, calculated nitrite intake in 4-year-old children generally exceeded the ADI. Moreover, the actual intake of nitrite from cured meat is dependent on the type of meat source, with a higher residual nitrite levels in chicken products compared with pork/beef products. This may result in increased nitrite exposure among consumers shifting their consumption pattern of processed meats from red to white meat products.

Estimated intakes of brominated flame retardants via diet and dust compared to internal concentrations in a Swedish mother-toddler cohort.

Tri-decabrominated diphenyl ethers (tri-decaBDEs), isomer-specific hexabromocyclododecanes (HBCDs) and 14 emerging brominated flame retardants (EBFRs) were determined in Swedish market basket samples, two pooled breast milk samples and house dust collected in homes of first-time mothers. Daily dietary and dust intakes were estimated for the mothers and their toddlers and compared to previously reported levels in serum of both the mothers and toddlers and in feces of the toddlers (n=20). Diet was the main contributor for intake of ΣpentaBDE and α-tetrabromoethylcyclohexane (DBE-DBCH) for both mothers and toddlers. For ΣoctaBDE, ΣHBCD and pentabromobenzene (PBBz), dietary intake was more important for mothers while house dust ingestion was more important for toddlers. House dust was the main exposure route for ΣdecaBDE, decabromodiphenyl ethane (DBDPE), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB), bis(2-ethylhexyl)tetrabromophthalate (BEH-TEBP), bis(2,4,6-tribromophenoxy) ethane (BTBPE) and pentabromotoluene (PBT) for both mothers and toddlers. Significant correlations (Spearmans, α<0.05) were found between the mothers' BDE serum concentrations and their consumption of meat and fish while no correlations were found between BFR dietary intake and serum or feces concentrations in toddlers. Octa-decaBDE congener concentrations in serum and feces of toddlers were significantly correlated to those in house dust. BDE-207 and -208 concentrations in serum of mothers were significantly correlated with the nonaBDEs in house dust. The correlations between house dust and internal concentrations and comparison of the house dust and dietary contributions to the estimated daily intakes suggest that dust exposure plays a larger role for the octa-decaBDE body burden in toddlers than in their mothers.

Time trends of polybrominated diphenylether (PBDE) congeners in serum of Swedish mothers and comparisons to breast milk data.

In the present study our main focus was blood serum levels and time trends of the fully brominated diphenyl ether (PBDE) BDE-209 in Swedish first-time mothers, as relatively a few human data on this congener are currently available. Also, levels and temporal trends in serum of other more commonly reported PBDE congeners and HBCD were studied. In an ongoing study on POPs in Uppsala Primiparas (POPUP), serum samples (N=413) from first-time mothers from 1996 to 2010 were used. Pooling of individual samples (5-25 individuals/pool, approx. 3 pools/year) resulted in 36 pooled samples used for PBDE/HBCD analysis on GC-LRMS. In addition, serum/breast milk correlations for PBDE and HBCD levels in 30 paired samples from individual mothers sampled 2010 were studied. The mean serum level of BDE-209 (1.3ng/g lipid wt.) was highest of all studied PBDE congeners, followed by BDE-47 and BDE-153. There was no significant temporal trend for BDE-209 during the study period, whereas the levels of BDE-47, BDE-99, BDE-100 and of HBCD decreased significantly in pooled serum 1996-2010. After omission of one outlier, a significant increasing trend was observed for BDE-153. The serum/milk PBDE quotients in paired individual samples from 2010 ranged from 0.83 to 17, with the highest quotient for BDE-209. Differences in PBDE transfer from blood to milk are probably related to molecular weight or size. The correlations between serum and milk levels of tetra- to hexa-brominated congeners were generally strong (r=0.83-0.97), but weaker for BDE-183 (r=0.57) and BDE-209 (r=0.38). Regarding HBCD, serum levels in 2010 were mostly beneath LOQ which made serum/milk quotients impossible. The decreasing levels of some BFR compounds in serum over time show that exposures have decreased after the production and use of some of these substances have been restricted. The lack of temporal trend of BDE-209 suggests that the human exposure to this congener in Sweden has been stable for more than a decade.

Perfluoroalkyl acids and their precursors in Swedish food: The relative importance of direct and indirect dietary exposure.

We analyzed food market basket samples obtained in Sweden from 1999, 2005, and 2010 for perfluoroalkyl acids (PFAAs) and a range of precursor compounds. Perfluorooctane sulfonic acid (PFOS) precursors were detected in all food year pools with the highest concentrations in 1999. Six polyfluoroalkyl phosphate diesters (diPAPs, 4:2/6:2, 6:2/6:2, 6:2/8:2, 8:2/8:2, 6:2/10:2, and 10:2/10:2) were detected in the year pools with the highest ∑diPAP concentrations in 1999 and 2005. All precursors were predominantly found in meat, fish, and/or eggs based on analysis of individual food groups from 1999. Based on year pools, PFOS precursors contributed between 4 and 1% as an indirect source to total dietary PFOS intakes between 1999 and 2010. Perfluorohexanoic acid (PFHxA) exposure originated entirely from diPAPs, whereas for perfluorooctanoic acid (PFOA) and perfluorodecanoic acid (PFDA), diPAPs contributed between 1 and 19% to total exposure. The lowest precursor contributions were generally seen in food samples from 2010.

Feasibility study of feces for noninvasive biomonitoring of brominated flame retardants in toddlers.

This study investigated the feasibility of using feces as a noninvasive matrix to estimate serum concentrations of brominated flame retardants (BFRs) in toddlers for biomonitoring purposes. Tri- to decabrominated diphenyl ethers (tri-decaBDEs), isomer-specific hexabromocyclododecanes, and 16 emerging BFRs were determined in feces from 22 toddlers (11-15 months of age), and results were compared to previously analyzed matched serum samples. BDE-47, -153, -196, -197, -203, -206, -207, -208, and -209 were detected in the feces creating a matched data set (feces-serum, n = 21). Tetra-octaBDE concentrations were significantly higher (Student's paired comparisons t test, α = 0.05) in serum versus feces with BDE-153 having the highest mean difference between the sample matrices. BDE-209 was found in significantly higher concentrations in feces compared to serum. Significant correlations (Pearson's, α = 0.05) between congener-specific concentrations in feces and serum were found for all BDEs except BDE-197 and -203. The feces-serum associations found can be used to estimate serum concentrations of tetra-decaBDEs from feces concentrations and enable a noninvasive sampling method for biomonitoring BDEs in toddlers.

Low intake of polycyclic aromatic hydrocarbons in Sweden: results based on market basket data and a barbecue study.

In a market basket study made at the National Food Agency in Sweden, in which the most common consumed foodstuffs are sampled, the content of polycyclic aromatic hydrocarbons (PAH), benzo(a)pyrene (B(a)P) and PAH4 (B(a)P, chrysene, benzo(b)fluoranthene, and benz(a)anthracene) were analysed. To this data, results on B(a)P and PAH4 levels originating from a home-barbecue-study on sausages and loin of pork were added. The calculated total mean intake of B(a)P and PAH4 was 50 ng/person and day 276 ng/person and day, respectively. Sugar and sweets, cereal products, meat, and dairy products contributed most to the total intake. In case of PAH concentrations below LOD, 0.03 µg/kg, ½ LOD was used in the intake calculations. The highest mean level of B(a)P and PAH4 were found in the barbecued products, but since the estimated consumption in Sweden is low, the contribution to the total food intake is almost negligible, about 2%. The calculated B(a)P levels in food has decreased during the last 10 years and indicates a low cancer risk for the Swedish population.

Brominated flame retardants in matched serum samples from Swedish first-time mothers and their toddlers.

Tri-decabrominated diphenyl ethers and 21 other flame retardants were determined in matched serum samples from 24 Swedish mothers (Uppsala county) and their toddlers (11-15 months of age). The median concentrations of individual polybrominated diphenyl ethers (PBDEs) ranged from 0.036 to 0.95 ng/g lipid in mothers and from 0.057 to 1.5 ng/g lipid in toddlers. BDE-209 was detected in all but one sample. BDE-153 was the predominant congener in the mothers while in toddlers, BDE-209 was found in the highest concentrations. The levels of BDE-47, -100, -207, -208, and -209 in toddlers were significantly higher (p < 0.05) than those in their mothers. Dechlorane Plus (anti- and syn-) and α- and ß-tetrabromoethylcyclohexane were detected in a few (2-4) serum samples from both mothers and toddlers. This study also reports concentrations of α-HBCD and eight emerging brominated flame retardants (EBFRs) in the standard reference material serum (SRM 1958, NIST). Lack of correlations between the matched serum samples indicate different exposure routes for octa-decaBDEs in mothers versus toddlers. Congener-to-congener correlations within the mother or toddler cohorts suggest diet as an important exposure pathway for tetra-nonaBDEs for mothers, breastfeeding as a predominant exposure pathway for tetra-hexaBDEs, and dust for octa-decaBDEs for toddlers.

Temporal trends (1999-2010) of perfluoroalkyl acids in commonly consumed food items.

The aim of this study was to determine how dietary exposure to PFAAs has changed over the period when major production changes occurred. Archived samples (1999-2010) of eggs, milk and farmed rainbow trout were analyzed by ultra performance liquid chromatography coupled to tandem mass spectrometry. Statistically significant decreasing trends were observed for concentrations of perfluorooctane sulfonic acid (PFOS) and perfluorohexane sulfonic acid (PFHxS) in fish (p < 0.002 and p < 0.032, respectively) and eggs (p < 0.001 for both compounds). Concentrations of PFOS in fish and eggs decreased by a factor of 10 and 40, respectively. In eggs there was also a statistically significant decreasing trend in concentrations of perfluorooctanoic acid (PFOA). The results of this study demonstrate that PFAA concentrations in food items from agricultural food chains and aquatic food chains close to sources respond rapidly to changes in environmental emissions. Implications for the overall understanding of human exposure are discussed.

Serum concentrations of perfluorinated alkyl acids and their associations with diet and personal characteristics among Swedish adults.

SCOPE: In this study, food is suggested as a major source of human exposure to perfluorinated alkyl acids (PFAA). We investigated relations between serum levels of PFAA in adults and diet/lifestyle factors nationwide in Sweden. METHODS AND RESULTS: In 2010-2011, adults (18-80 years, N = 270) recorded their diet for 4 days and answered a food frequency questionnaire. PFAA were measured in blood serum as well as v-3 fatty acids in plasma phospholipids as a biomarker for fish consumption. Higher levels of PFAA were associated with male sex, increased age, and higher education. Women reporting full breastfeeding for ≥12 months had 32-44% lower levels of perfluorooctane sulfonate, perfluorooctanoic acid, and perfluorohexane sulfonate than women who never nursed their infants full-time. Serum perfluorooctane sulfonate, perfluorononanoic acid, perfluorodecanoic acid, and perfluoroundecanoic acid were positively related to n-3 fatty acids in plasma (partial r = 0.19-0.34, p ≤ 0.05). CONCLUSION: The relatively strong correlations between biomarkers of fish consumption and certain PFAA suggest that PFAA exposure should be taken into account in health risk and benefit assessment of fish consumption. Breastfeeding appears to be a major source of elimination of certain PFAA among women, and consequently PFAA exposure of nursed infants could be significant.

Prenatal exposure to polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) may influence birth weight among infants in a Swedish cohort with background exposure: a cross-sectional study.

BACKGROUND: Prenatal exposure to persistent organic pollutants, e.g. polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) has been suggested to negatively affect birth weight although epidemiological evidence is still inconclusive. We investigated if prenatal exposure to PCBs and PBDEs is related to birth weight in a Swedish population with background exposure. METHODS: Breast milk was sampled during the third week after delivery from first-time mothers in Uppsala county, Sweden 1996-2010 (POPUP cohort) (N = 413). Samples were analysed for di-ortho PCBs (CB-138, 153, 180) and tetra- to hexa- brominated PBDEs (BDE-47, 99, 100, 153). Simple and multiple linear regression models were used to investigate associations between lipid-adjusted, ln-transformed PCB and PBDE concentrations, and birth weight. Covariates included in the multivariate regression model were PCB and PBDE exposure, maternal age, pre-pregnancy BMI, weight gain during pregnancy, education, smoking, gender of the infant and gestational length. The effect of including fish consumption was also investigated. RESULTS: In the multivariate model, prenatal exposure to di-ortho PCBs was significantly associated with increased birth weight (ß = 137; p = 0.02). The result did not change when gestational length was added to the model. An inverse association between PBDE(4) (sum of BDE-47, -99, -100 and -153) and birth weight was observed in the multivariate model including gestational length (ß = -106; p = 0.04). Maternal pre-pregnancy BMI and weight gain during pregnancy were important confounders of the association between di-ortho PCBs and birth weight. The associations were not alleviated after adjustment for fish consumption, a major source of PCB and PBDE exposure. The observed associations were stronger for boys than for girls. CONCLUSIONS: Our results indicate that prenatal exposure to di-ortho PCBs and PBDE(4) may influence birth weight in different directions, i.e. PCB exposure was associated with higher birth weight and PBDE exposure with lower birth weight. Maternal pre-pregnancy BMI and weight gain during pregnancy were important confounders that may hide positive association between di-ortho PCB exposure and birth weight if they are not included in the statistical model. We speculate that even small PCB- and PBDE-induced shifts in the distribution of birth weight may influence future public health in populations with background exposure.

Lead, mercury, and cadmium in blood and their relation to diet among Swedish adults.

The aim of the present study was to examine the body burden of lead (Pb), mercury (Hg), and cadmium (Cd) in blood among Swedish adults and the association between blood levels, diet and other lifestyle factors. The study was based on a subgroup (n=273) of the national survey Riksmaten 2010-2011 (4-day food records and questionnaire). Lead, Hg, and Cd were measured in whole blood, and Cd additionally in urine, by mass or fluorescence spectrometry methods. The median values (5-95th percentiles) of the metals in blood were as follows; Pb: 13.4 (5.8-28.6) µg/L, Hg: 1.13 (0.31-3.45) µg/L, and Cd: 0.19 (0.09-1.08) µg/L. All three metals increased with increasing age. Lead levels in blood were positively associated with intakes of game and alcohol, Hg was related to fish intake, and blood Cd related to smoking and low iron stores and to a low meat intake. Body burdens of the studied metals were generally below health based reference values, but several individuals had blood Pb levels above the reference point for possible nephrotoxic and developmental neurotoxic effects. As health effects cannot be excluded, individuals with high Pb exposure should aim at decreasing their body burden, both from food and from other exposure routes.

The flame-retardant BDE-99 dose-dependently affects viral replication in CVB3-infected mice.

The flame retardant component 2,2',4,4',5-penta-BDE (BDE-99) is found in the environment and in human tissues and fluids. In mice the common human coxsackievirus B3 (CVB3) infection has been shown to change the tissue distribution of BDE-99. We now investigate how CVB3 infection in mice affects liver uptake of (14)C at two doses of radiolabelled BDE-99, and whether increased tissue levels are related to changed virus replication and gene expression of the proinflammatory chemokine monocyte chemoattractant protein-1 (MCP-1). Mice were infected on day 0, orally treated either with 200µg or 20mg (14)C-BDE-99/kgbw on day 1, and euthanised on day 3. Serum and liver levels of (14)C-BDE-99, as well as virus levels and gene expressions of MCP-1 in the liver, were measured. In non-infected mice, there was a dose-dependent uptake of BDE-99 in both liver and serum, and in infected animals the liver BDE-99 levels was further increased. When comparing infected mice exposed to the two BDE-99 doses, the higher BDE dose resulted in increased virus amounts in the liver, and decreased infection-induced expression of MCP-1. Consequently, a high enough dose/tissue concentration of BDE-99 may result in a disturbed mobilisation of immune cells into infected tissues that could explain higher virus titres and a possibly altered clinical course of the disease. Moreover, the fact that CVB3 infection increased the BDE-99 levels in liver but not in serum may impair the risk assessment of polybrominated diphenyl ethers (PBDEs) in subclinical and clinically infected individuals, as serum levels is the common marker of exposure.

Fish intake and breastfeeding time are associated with serum concentrations of organochlorines in a Swedish population.

Persistent organic pollutants (POPs) exert harmful effects on cognitive, endocrine and immune functions and bioaccumulate in the environment and human tissues. The aim of this study was to investigate the body burden of several POPs in the adult population (n=246) and their association to diet and other lifestyle factors in a Swedish national survey. Serum concentrations of several polychlorinated biphenyls (PCBs), and the pesticides hexachlorobenzene (HCB), ß-hexachlorocyclohexane (ß-HCH), chlordane compounds and dichlorodiphenyldichloroethylene (DDE) were determined by liquid-liquid extraction, silica column cleanup and gas chromatography high resolution mass spectrometry. Diet was assessed using 4-day food records and complementary dietary and lifestyle factors by questionnaire. Fish intake was additionally assessed by plasma fatty acid composition. Clustering of the compounds revealed that PCBs were separated into two clusters, one including low-chlorinated PCB 28 and 52, and the other high-chlorinated mono- and di-ortho PCBs, suggesting similarities and dissimilarities in exposure sources and possibly also toxicokinetics. Men had 24% and 32% higher levels of PCB 138-180 and chlordane compounds, respectively, compared with women. This may partly be explained by elimination of the POPs among women reporting a history of breastfeeding. The proportion of very long-chain n-3 fatty acids in plasma were positively correlated with the pollutants: r=0.24 (PCB 28), r=0.33 (PCB 118), r=0.35 (PCB 138-180), r=0.29 (HCB), r=0.18 (ß-HCH), r=0.34 (chlordane compounds), r=0.34 (p,p'-DDE), p≤0.005. Individuals consuming fatty Baltic fish≥1 time per months had 45% higher serum levels of PCB 118 compared with non-consumers. Levels of PCB 28 were associated with the age of the residential building. To conclude, the population-distributed approach of surveying dietary habits, lifestyle factors and POP body burdens, made it possible to identify personal characteristics associated with the POP body burdens in Sweden.

Perfluorinated alkyl acids in blood serum from primiparous women in Sweden: serial sampling during pregnancy and nursing, and temporal trends 1996-2010.

We investigated temporal trends of blood serum levels of 13 perfluorinated alkyl acids (PFAAs) and perfluorooctane sulfonamide (FOSA) in primiparous women (N = 413) from Uppsala County, Sweden, sampled 3 weeks after delivery 1996-2010. Levels of the short-chain perfluorobutane sulfonate (PFBS) and perfluorohexane sulfonate (PFHxS) increased 11%/y and 8.3%/y, respectively, and levels of the long-chain perfluorononanoate (PFNA) and perfluorodecanoate (PFDA) increased 4.3%/y and 3.8%/y, respectively. Concomitantly, levels of FOSA (22%/y), perfluorooctane sulfonate (PFOS, 8.4%/y), perfluorodecane sulfonate (PFDS, 10%/y), and perfluorooctanoate (PFOA, 3.1%/y) decreased. Thus, one or several sources of exposure to the latter compounds have been reduced or eliminated, whereas exposure to the former compounds has recently increased. We explored if maternal levels of PFOS, PFOA, and PFNA during the early nursing period are representative for the fetal development period, using serial maternal serum samples, including cord blood (N = 19). PFAA levels in maternal serum sampled during pregnancy and the nursing period as well as in cord blood were strongly correlated. Strongest correlations between cord blood levels and maternal levels were observed for maternal serum sampled shortly before or after the delivery (r = 0.70-0.89 for PFOS and PFOA). A similar pattern was observed for PFNA, although the correlations were less strong due to levels close to the method detection limit in cord blood.