Temporal trends of per- and polyfluoroalkyl substances concentrations: Insights from Australian human biomonitoring 2002-2021 and the U.S. NHANES programs 2003-2018.

Perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS), and perfluorononanoic acid (PFNA) are persistent contaminants detected in human blood worldwide, raising significant health concerns. In response, countries such as the United States and Australia have implemented regulatory measures to limit their use. This study analysed temporal trends in serum concentrations of these four PFAS and how these trends align with regulatory measures, using data from NHANES (2003-2004 to 2017-2018) and the Australian Human Biomonitoring Program (2002-2003 to 2020-2021). Multiple regression analyses adjusted for age and gender were performed to estimate mean concentration changes over time, and differences within each dataset were assessed. Results indicated significant reductions (p < 0.001) in PFOS, PFOA, and PFHxS concentrations post-2002-2003, while PFNA concentrations increased until 2009-2010 before declining in both Australia and the U.S. Age-related trends in the U.S. during the last monitoring period showed higher PFAS concentrations in the oldest age groups, while in Australia, this trend was evident for PFOS and PFHxS. In Australia, the age group of 0-5 years had PFOA and PFNA concentrations similar to those of adults over 46 years, indicating ongoing exposure. Gender differences were consistent in both programs, with females aged 6-15, 31-45, and 46-60 years exhibiting lower serum concentrations, particularly in the 31-45 years age group. These findings support Australian and U.S. efforts to reduce PFAS exposure through regulatory actions, highlight the need to address ongoing exposure in young children, and consider gender-specific factors affecting PFAS concentrations.

Biomonitoring in firefighters for volatile organic compounds, semivolatile organic compounds, persistent organic pollutants, and metals: A systematic review.

Firefighters are exposed to a wide range of toxic chemicals due to combustion, with numerous biomonitoring studies completed that have assessed exposure. Many of these studies focus on individual classes of chemicals, with a few considering a broad range of systemic exposures. As yet, no review process has been undertaken to comprehensively examine these studies. The aims of this review are to: (1) ascertain whether biomonitoring studies pertaining to firefighters demonstrate occupational exposure to volatile organic compounds, semivolatile organic compounds, and metals; (2) determine and present results of biomonitoring studies; (3) provide any recommendations presented from the literature that may support exposure mitigation; and (4) suggest future study parameters that may assist in providing a greater understanding surrounding the occupational exposure of firefighters. A systematic review was undertaken with regards to firefighters and biomonitoring studies utilising the matrices of blood, urine, semen and breast milk. This yielded 5690 results. Following duplicate removal, inclusion and exclusion criteria screening and full text screening, 34 studies remained for review. Results of over 80% of studies analysed determined firefighters to experience occupational exposure. Results also show firefighters to be exposed to a wide range of toxic chemicals due to fire smoke; potentially exceeding the range of exposure of other occupations. As firefighters may face increased risk of health effects due to the additive, synergistic, and/or antagonistic effects of chemical exposure, all care must be taken to reduce exposure. This may be achieved by considering tactical decisions, increased personal hygiene, and thorough decontamination procedures. Future biomonitoring studies recognising and assessing the range of chemical exposure firefighters face would be beneficial.

Analysis of urinary metabolites of polycyclic aromatic hydrocarbons and cotinine in pooled urine samples to determine the exposure to PAHs in an Australian population.

Our previous biomonitoring study of hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) in a population in Australia found high levels of 1-naphthol, a metabolite of both naphthalene and carbaryl, in some adult samples. Here, we conducted a follow-up study to collect and analyse pooled urine samples, stratified by age and sex, from 2014 to 2017 using a GC-MS method. Geometric mean concentrations of 1-hydroxypyrene, the most common biomarker of PAH exposure, were 100 and 120 ng/L urine in 2014-2015 and 2016-2017, respectively. The concentrations of most OH-PAHs in this study except 1-naphthol are in line with those reported by biomonitoring programs in the US and Canada. In general, concentrations of OH-PAHs are lower in samples from small children (0-4 years) and school-aged children (5-14 years) compared with samples from the older age groups, except for some cases in the recent monitoring period. The concentrations of 1-naphthol in some adult samples of both sexes are very high, which is consistent with our previous findings. Such high concentrations of 1-naphthol together with the high 1-naphthol/2-naphthol ratio suggest potential exposure to the insecticide carbaryl in this population but other exposure sources and different rates of naphthalene metabolism should also be investigated.

Per- and poly-fluoroalkyl substances (PFASs) in follicular fluid from women experiencing infertility in Australia.

Per- and poly-fluoroalkyl substances (PFASs) have been widely used and detected in human matrices. Evidence that PFAS exposure may be associated with adverse human reproductive health effects exists, however, data is limited. The use of a human matrix such as follicular fluid to determine chemical exposure, along with reproductive data will be used to investigate if there is a relationship between PFAS exposure and human fertility. OBJECTIVE: This study aims to: (1) assess if associations exist between PFAS concentrations and/or age and fertilisation rate (as determined in follicular fluid of women in Australia who received assisted reproductive treatment (ART)); and (2) assess if associations exist between PFAS concentrations and infertility aetiology. METHODS: Follicular fluids were originally collected from participants who underwent fully stimulated ART treatment cycles at an in vitro fertilisation (IVF) clinic in the period 2006-2009 and 2010-11 in Queensland, Australia. The samples were available for analysis of 32 PFASs including perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonate (PFHxS), and perfluorononanoic acid (PFNA) using high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). 97 samples were matched with limited demographic data (age and fertilisation rate) and five infertility factors (three known female factors): 1) endometriosis, 2) polycystic ovarian syndrome (PCOS), and 3) genital tract infections - tubal/pelvic inflammation disease; as well as 4) male factor, and 5) idiopathic or unknown from either males or females. SPSS was used for linear regression analysis. RESULTS: PFASs were detected in all follicular fluid samples with the mean concentrations of PFOS and PFOA, 4.9, and 2.4 ng/ml, respectively. A lower fertilisation rate was observed at higher age when age was added as a covariate, but there was no relationship between PFAS concentrations and fertilisation rate. There were few statistically significant associations between PFAS concentrations in follicular fluid and infertility factors. Log-transformed PFHxS concentrations were lower in females with endometriosis (factor 1) than in women who had reported 'male factors' as a reason of infertility, while PFHpA was higher in women who had infertile due to female factors (factor 1-3) compared to those who had infertile due to male factor. CONCLUSION: PFASs were detected in follicular fluid of Australian women who had been treated at an IVF clinic. PFAS exposure found in follicular fluids is linked to increased risk of some infertility factors, and increased age was associated with decreased fertilisation rate in our data. But there was no relationship between PFAS and ferlitisation rate. Further large-scale investigations of PFAS and health effects including infertility are warranted.

Monitoring the levels of brominated and organophosphate flame retardants in passenger cars: Utilisation of car air filters as active samplers.

Filters in residential and office air conditioning (A/C) systems have been used as sampling devices for monitoring different pollutants. However, cabin air filters (CAFs) in the A/C system of passenger cars have not been utilised for this purpose. In this study, we collected 22 used CAFs from passenger cars in Hanoi, Vietnam to analyse for 8 polybrominated diphenyl ethers (PBDEs) and 10 organophosphate esters (OPEs). All the analytes were detected in more than 50% of samples with the exception of BDE153 and BDE154. The average concentrations of ∑10OPEs and ∑8BDEs in the captured dust were 2600 and 40 ng/g, respectively with Tris (1-chloro-2-propyl) phosphate (TCIPP) and BDE209 as the dominant congener in OPE and BDE groups, respectively. CAFs are a potential tool to qualitatively assess the levels of semi-volatile chemicals in suspended dust in cars as a screening step for exposure assessment of those chemicals.

A systematic review: Impact of endocrine disrupting chemicals exposure on fecundity as measured by time to pregnancy.

BACKGROUND: Emerging scientific evidence suggests that exposure to environmental pollutants is associated with negative effects on fecundity as measured by time to pregnancy (TTP). OBJECTIVES: To conduct a systematic review of the literature on the association between selected endocrine disrupting chemicals (EDCs), and fecundity as measured by TTP in humans. Compounds included in this review are: brominated flame retardants (BFRs) such as hexabromocyclododecane, tetrabromobiphenol A and polybrominated diphenyl ethers; organophosphates flame retardants (OPFRs); and phthalates. METHODS: Scopus, MEDLINE via Ebscohost and EMBASE databases were searched for articles exploring the relationships between selected EDCs and fecundity as measured by time to pregnancy. We assessed the quality of included studies and evidence for causality was graded using the criteria developed by the World Cancer Research Fund. RESULTS: 14 studies of 191 full-text articles assessed for eligibility were included for qualitative synthesis. Five studies examined BFRs and 10 studies examined phthalates. Among the fourteen, one study assessed both BFRs and phthalates. There were no studies which investigated fecundity as measured by TTP on HBCD, TBBPA, or OPFRs. We recorded plausible fecundity outcomes as measured by TTP related to some of these EDCs. BFRs or phthalates increased TTP. However, results were inconsistent. CONCLUSION: We recorded mostly weak associations between exposure to selected EDCs and fecundity. However, evidence was considered limited to conclude a causal relationship due to inconsistency of results. The health risks posed by these chemicals in exposed populations are only beginning to be recognized and prospective measurement of the environmental effects of the chemicals in large cohort studies are urgently needed to confirm these relationships and inform policies aimed at exposure prevention.

Pesticide metabolite concentrations in Queensland pre-schoolers - Exposure trends related to age and sex using urinary biomarkers.

This study aimed to assess pesticide concentration and composition trends associated with age and sex in Australian infants and toddlers. Individual urine samples (n = 400) were collected in 2014/5 from Queensland infants and toddlers aged 0-5 y and composited into 20 pools of 20 individual samples by age (of 5 strata) and sex. Nineteen biomarkers including organophosphate and pyrethroid pesticide metabolites, herbicides and metabolites, and an insect repellent, DEET, were measured. In total, seven organophosphate pesticide metabolites, three pyrethroid metabolites and one herbicide metabolite were detectable in >50% of the sample pools. A significant increase of concentrations of dimethyl phosphate, dimethyl dithiophosphate, diethyl thiophosphate (DETP), 3,5,6-trichloro-2-pyridinol (TCPY), 4-nitrophenol and 3-phenoxybenzoic acid with age was observed (with the p value of <0.0001 to 0.034). This suggested that exposure increases following weaning or as a result of increased dietary intake and mobility/activity. Significant age trends remained after adjustment for body weight and urine flow for DETP and TCPY (p = 0.029 and 0.016 respectively). The level of estimated "worst-case scenario" daily intake of chlorpyrifos from these pooled samples ranged from 0.40 to 1.8 µg/kg-day, which was below the Australian Acceptable Daily Intake guideline (3 µg/kg-day). This study presents the first dataset of age trends in concentrations of these pesticides for infants and toddlers and contributed to new understanding of exposure pathways and potential risks.

Demographic and temporal trends of hexabromocyclododecanes (HBCDD) in an Australian population.

Hexabromocyclododecanes (HBCDD) were measured in 67 pooled serum samples collected between 2002 and 2015 in South East Queensland, Australia. These data are the first report of HBCDD in Australian human serum. Temporal and demographic (age and gender) trends were investigated. HBCDD were detected in measurable concentrations in 69% of samples. The average ∑HBCDD concentration was 3.1ng/g lipid, whilst the range was <0.5 to 36ng/g lipid. α-HBCDD was the dominant stereoisomer making up an average of 60% of ∑HBCDD. The remainder was made up by γ-HBCDD. In contrast to another group of brominated flame retardants (BFRs, (polybrominated diphenyl ethers (PBDEs)), HBCDD were found in the lowest concentrations in pools from children aged 0-4 years. This could be attributed to differences in exposure, usage, and/ or the much lower half-life of HBCDD in the human body compared to PBDEs. HBCDD concentrations appear to be significantly higher in females than in males, however the reasons for this are unclear.

Monthly variation in faeces:blood concentration ratio of persistent organic pollutants over the first year of life: a case study of one infant.

Previous studies have found that the concentrations of a range of persistent organic pollutants (POPs) in faeces is linearly proportional to the POP concentrations in blood of human adults irrespective of age and gender. In order to investigate the correlation between POP concentrations in faeces and blood in infants, the monthly variation of POP concentrations in faeces over the first year of life of one infant was investigated in this study and compared to modelled blood concentrations. Faecal samples were collected from one male infant daily. The samples were pooled by month and analysed for three selected POPs (2,2('),4,4('),5,5(')-Hexachlorobiphenyl (PCB153), p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) and 2,2('),4,4'-tetrabromodiphenyl ether (BDE47)). The POP concentrations in faecal samples increased for the first four months by a factor of 2.9, 4.9 and 1.4 for PCB153, BDE47, and p,p'-DDE, respectively. The faecal concentrations of all POPs decreased rapidly following the introduction of formula and solid food to the diet and subsequent weaning of the infant. Further, a one-compartment model was developed to estimate the daily POP concentrations in the blood of the infant. The POP concentrations in blood were predicted to vary much less over the first year than those observed in faeces. The faeces:blood concentration ratio of selected POPs (Kfb) differed significantly (P<0.0001) between the period before and after weaning, and observed changes in Kfb are far greater than the uncertainty in the estimated Kfb. A more stable Kfb after weaning indicates the possibility of applying the stable Kfb values for non-invasive assessment of internal exposure in infants after weaning. The intra-individual variation in Kfb in infants is worthy of further investigation.

Novel fluorinated surfactants tentatively identified in firefighters using liquid chromatography quadrupole time-of-flight tandem mass spectrometry and a case-control approach.

Fluorinated surfactant-based aqueous film-forming foams (AFFFs) are made up of per- and polyfluorinated alkyl substances (PFAS) and are used to extinguish fires involving highly flammable liquids. The use of perfluorooctanesulfonic acid (PFOS) and other perfluoroalkyl acids (PFAAs) in some AFFF formulations has been linked to substantial environmental contamination. Recent studies have identified a large number of novel and infrequently reported fluorinated surfactants in different AFFF formulations. In this study, a strategy based on a case-control approach using quadrupole time-of-flight tandem mass spectrometry (QTOF-MS/MS) and advanced statistical methods has been used to extract and identify known and unknown PFAS in human serum associated with AFFF-exposed firefighters. Two target sulfonic acids [PFOS and perfluorohexanesulfonic acid (PFHxS)], three non-target acids [perfluoropentanesulfonic acid (PFPeS), perfluoroheptanesulfonic acid (PFHpS), and perfluorononanesulfonic acid (PFNS)], and four unknown sulfonic acids (Cl-PFOS, ketone-PFOS, ether-PFHxS, and Cl-PFHxS) were exclusively or significantly more frequently detected at higher levels in firefighters compared to controls. The application of this strategy has allowed for identification of previously unreported fluorinated chemicals in a timely and cost-efficient way.

Polybrominated diphenyl ethers (PBDEs) in dust from primary schools in South East Queensland, Australia.

PBDE concentrations are higher in children compared to adults with exposure suggested to include dust ingestion. Besides the home environment, children spend a great deal of time in school classrooms which may be a source of exposure. As part of the "Ultrafine Particles from Traffic Emissions and Children's Health (UPTECH)" project, dust samples (n=28) were obtained in 2011/12 from 10 Brisbane, Australia metropolitan schools and analysed using GC and LC-MS for polybrominated diphenyl ethers (PBDEs) -17, -28, -47, -49, -66, -85, -99, -100, -154, -183, and -209. Σ11PBDEs ranged from 11-2163 ng/g dust; with a mean and median of 600 and 469 ng/g dust, respectively. BDE-209 (range n.d. -2034 ng/g dust; mean (median) 402 (217)ng/g dust) was the dominant congener in most classrooms. Frequencies of detection were 96%, 96%, 39% and 93% for BDE-47, -99, -100 and -209, respectively. No seasonal variations were apparent and from each of the two schools where XRF measurements were carried out, only two classroom items had detectable bromine. PBDE intake for 8-11 year olds can be estimated at 0.094 ng/day BDE-47; 0.187 ng/day BDE-99 and 0.522ng/day BDE-209 as a result of ingestion of classroom dust, based on mean PBDE concentrations. The 97.5% percentile intake is estimated to be 0.62, 1.03 and 2.14 ng/day for BDEs-47, -99 and -209, respectively. These PBDE concentrations in dust from classrooms, which are higher than in Australian homes, may explain some of the higher body burden of PBDEs in children compared to adults when taking into consideration age-dependant behaviours which increase dust ingestion.

Assessing exposure to polybrominated diphenyl ethers (PBDEs) for workers in the vicinity of a large recycling facility.

Increased levels of polybrominated diphenyl ethers (PBDEs) can occur particularly in dust and soil surrounding facilities that recycle products containing PBDEs. This may be the source of increased exposure for nearby workers and residents. To investigate, we measured PBDE levels in soil, office dust and blood of workers at the closest workplace (i.e. within 100m) to a large automotive shredding and metal recycling facility in Brisbane, Australia. The workplace investigated in this study was independent of the automotive shredding facility and was one of approximately 50 businesses of varying types within a relatively large commercial/industrial area surrounding the recycling facility. Concentrations of PBDEs in soils were at least an order of magnitude greater than background levels in the area. Congener profiles were dominated by larger molecular weight congeners; in particular BDE-209. This reflected the profile in outdoor air samples previously collected at this site. Biomonitoring data from blood serum indicated no differential exposure for workers near the recycling facility compared to a reference group of office workers, also in Brisbane. Unlike air, indoor dust and soil sample profiles, serum samples from both worker groups were dominated by congeners BDE-47, BDE-153, BDE-99, BDE-100 and BDE-183 and was similar to the profile previously reported in the general Australian population. Estimated exposures for workers near the industrial point source suggested indoor workers had significantly higher exposure than outdoor workers due to their exposure to indoor dust rather than soil. However, no relationship was observed between blood PBDE levels and different roles and activity patterns of workers on-site. These comparisons of PBDE levels in serum provide additional insight into the inter-individual variability within Australia. Results also indicate congener patterns in the workplace environment did not match blood profiles of workers. This was attributed to the relatively high background exposures for the general Australian population via dietary intake and the home environment.

An Exploratory Analysis of Firefighter Reproduction through Survey Data and Biomonitoring.

Firefighters are occupationally exposed to chemicals that may affect fertility. To investigate this effect, firefighters were recruited to contribute blood, urine, breast milk or semen samples to (1) evaluate chemical concentrations and semen parameters against fertility standards and the general population; (2) assess correlations between chemical concentrations and demographics, fire exposure and reproductive history; and (3) consider how occupational exposures may affect reproduction. A total of 774 firefighters completed the online survey, and 97 firefighters produced 125 urine samples, 113 plasma samples, 46 breast milk samples and 23 semen samples. Blood, urine and breast milk samples were analysed for chemical concentrations (semivolatile organic compounds, volatile organic compounds, metals). Semen samples were analysed for quality (volume, count, motility, morphology). Firefighter semen parameters were below WHO reference values across multiple parameters. Self-reported rates of miscarriage were higher than the general population (22% vs. 12-15%) and in line with prior firefighter studies. Estimated daily intake for infants was above reference values for multiple chemicals in breast milk. More frequent fire incident exposure (more than once per fortnight), longer duration of employment (≥15 years) or not always using a breathing apparatus demonstrated significantly higher concentrations across a range of investigated chemicals. Findings of this study warrant further research surrounding the risk occupational exposure has on reproduction.

Spatial mapping of city-wide PBDE levels using an exponential decay model.

Passive air samplers (PAS) consisting of polyurethane foam (PUF) disks were deployed at 6 outdoor air monitoring stations in different land use categories (commercial, industrial, residential and semi-rural) to assess the spatial distribution of polybrominated diphenyl ethers (PBDEs) in the Brisbane airshed. Air monitoring sites covered an area of ~1143 km(2) and PAS were allowed to accumulate PBDEs in the city's airshed over three consecutive seasons commencing in the winter of 2008. The average sum of five (∑(5)) PBDEs (BDEs 28, 47, 99, 100 and 209) levels were highest at the commercial and industrial sites (12.7 ± 5.2 ng PUF(-1)), which were relatively close to the city center and were a factor of 8 times higher than residential and semi-rural sites located in outer Brisbane. To estimate the magnitude of the urban 'plume' an empirical exponential decay model was used to fit PAS data vs. distance from the CBD, with the best correlation observed when the particulate bound BDE-209 was not included (∑(5)-209) (r(2) = 0.99), rather than ∑(5) (r(2) = 0.84). At 95% confidence intervals the model predicts that regardless of site characterization, ∑(5)-209 concentrations in a PAS sample taken between 4-10 km from the city centre would be half that from a sample taken from the city centre and reach a baseline or plateau (0.6 to 1.3 ng PUF(-1)), approximately 30 km from the CBD. The observed exponential decay in ∑(5)-209 levels over distance corresponded with Brisbane's decreasing population density (persons/km(2)) from the city center. The residual error associated with the model increased significantly when including BDE-209 levels, primarily due to the highest level (11.4 ± 1.8 ng PUF(-1)) being consistently detected at the industrial site, indicating a potential primary source at this site. Active air samples collected alongside the PAS at the industrial air monitoring site (B) indicated BDE-209 dominated congener composition and was entirely associated with the particulate phase. This study demonstrates that PAS are effective tools for monitoring citywide regional differences however, interpretation of spatial trends for POPs which are predominantly associated with the particulate phase such as BDE-209, may be restricted to identifying 'hotspots' rather than broad spatial trends.

Effects of firefighting on semen parameters: an exploratory study.

Firefighters are occupationally exposed to heat intensities and chemical concentrations that may affect fertility. Twenty firefighters participated in an exploratory study assessing fertility of firefighters via an online survey and semen analysis. Data analysis included consideration of demographic characteristics, reproductive history and occupational exposures. Overall, firefighter semen parameters were below World Health Organisation reference values designating fertility in men. Firefighters younger than 45 years had a higher incidence of abnormal semen parameters (42%) than those aged 45 years or greater (9%). Increased rank and higher levels of occupational and/or personal hygiene were associated with improved semen quality. Increased frequency of fire exposure was associated with a reduction in normal forms, volume, sperm concentration and total sperm count. Sperm clumping was greater than 10% in 26% of samples, suggesting reduced semen quality. This exploratory study provides novel data that support the hypothesis of an association between semen quality and firefighter's occupational exposure to toxic environments.

Concentrations of phthalate metabolites in Australian urine samples and their contribution to the per capita loads in wastewater.

Exposure to phthalates is a public health concern. In this study, we collected both urine and wastewater samples from 2012 to 2017 and analysed for 14 phthalate metabolites to assess human exposure to phthalates in Southeast Queensland (SEQ), and for associations between phthalate metabolites in urine and wastewater samples. Twenty-four pooled urine samples were prepared from 2400 individual specimens every two years (stratified by age, gender and collection year). Wastewater samples were collected from the three major wastewater treatment plants (WWTPs) representing locations in the SEQ region including a regional city, part of the state capital city and a third major urban WWTP in the region. Over the period, decreases for most phthalate metabolites, i.e. mono-butyl phthalate (MBP), mono-isobutyl phthalate (MiBP), monobenzyl phthalate (MBzP), monocyclohexyl phthalate (MCHP), mono(3-carboxypropyl) phthalate (MCPP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), and monomethyl phthalate (MMP), but an increase in monoethyl phthalate (MEP, particularly in young children) were observed in urine. In general, temporal changes were smaller in urine pools representing older age groups. We also found substantial variation in per capita mass loads of phthalate metabolites between samples from the three WWTPs with generally higher concentrations of most phthalates in the metropolitan areas. Per capita mass loads of most phthalate metabolites in wastewater were higher than would be expected from the per-capita excretion in urine, suggesting there are additional sources contributing to the majority of the observed phthalate metabolites in wastewater. For MEHHP and MEOHP we estimate that the urinary excretion accounts for a substantial fraction (average about 50%) of the mass load observed in the wastewater hence wastewater data may provide useful for monitoring trends in exposure.

Evaluating age and temporal trends of chlorinated paraffins in pooled serum collected from males in Australia between 2004 and 2015.

Chlorinated paraffins (CPs) are high production volume chemicals of which some show resistance to environmental degradation, long-rang transport, bioaccumulation and toxicity potential. Information regarding their presence in humans is limited, including their human bioaccumulation potential. The present study aimed to evaluate CP levels in human serum from Australia in order to better understand their exposure and current pollution status as well as trends associated with age and time between 2004 and 2015. For this, we selected a male sub-group of the Australian population under 60 years old (n = 16 pools, total 1600 serum samples). While long-chain CP (C18-20) and most short-chain CP (C10-13, SCCPs) levels were below method detection limits (MDL), medium-chain CPs (C14-17, MCCPs) were found in most serum samples (detection frequency 94%) as well as CPs with a carbon chain length of nine (detection frequency 76%). The levels of ΣSCCPs and ΣMCCPs ranged from

Human biomonitoring in Australian children: Brominated flame retardants decrease from 2006 to 2015.

Polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCDD) were used intensively as flame retardants, worldwide. They have been detected in human serum samples and PBDEs have been found to be elevated in young children. Commercial Penta- and Octa-PBDE mixtures were banned in Australia in 2005, while HBCDD was banned worldwide in 2013. We investigated PBDE and HBCDD concentrations in serum collected from young children. We also investigated temporal trends in PBDE concentration 10 years after their Australian ban. Surplus human blood serum samples were collected through a pathology clinic (n = 800), in 2014/15, stratified by age (0-6, 6-12, 12-18, 18-24, 24-30, 30-36, 36-42, 42-48, 48-54 and 54-60 months) and sex and pooled for analysis of PBDEs (BDEs -28, -47, -99, -100, -153, -154, -183) and HBCDD. In 2014/15, the geometric mean concentration of the sum of all PBDEs measured (ΣPBDEs) was 4.5 ng/g lipid (median: 4.6 ng/g lipid, range: 0.88-26 ng/g lipid). A positive association between BDE-47 concentration and age was observed (R = 0.41, p = 0.008), however there were no trends between other PBDE congeners or HBCDD and age. There were no significant differences between genders for PBDEs (t-test, p = 0.802) or HBCDD (t-test, p = 0.740).The highest concentrations observed were in pools from the females 30-36 month (26 ng/g lipid) and Males 6-12 month (21 ng/g lipid) categories. BDEs -47 and -99 were the predominant congeners with a combined average contribution of 75% of ΣPBDEs. PBDEs showed a significant reduction in children aged 0-4 years over an eight year period. In 2014/15, the mean (range) concentration of BDE-47 is 2.8 (0.23 to 11) ng/g lipid compared to pools in 2006/07 at 19 (3-55) ng/g lipid (p < 0.0001) and for BDE-153 is 0.73 (<0.1 = -2.9) ng/g lipid compared to pools in 2006/07 at 4.7 (2-10) ng/g lipid (p < 0.0001). HBCDD concentrations were lower than PBDEs with a mean concentration of 0.45 ng/g lipid. There were no temporal trends observed for HBCDD when compared to samples collected in 2012. The dominant stereoisomer was α-HBCDD (mean = 0.38 ng/g lipid) with an average contribution of 65% towards ΣHBCDD. Levels of PBDEs in young Australian children have significantly decreased since the bans of commercial Penta- and Octa-BDE in 2005. There has been no observed decrease in HBCDD levels in Australian children since its ban in 2012.

Polybrominated diphenyl ethers (PBDEs) in sediment by salinity and land-use type from Australia.

Brominated flame retardants, including polybrominated diphenyl ethers (PBDEs) have been incorporated in numerous products to reduce flammability. Depending on their bromination, PBDEs are relatively persistent in the environment and have the potential to bioaccumulate through the food web. The present study was initiated to provide a better understanding on the levels and possible origin of PBDEs in the aquatic environment of Australia. PBDEs were detected at 35 out of 46 sites and concentrations were relatively low in the majority of samples analysed. Mean+/-standard deviation and median SigmaPBDE concentrations across all sites were 4707+/-12,580 and 305 pg g(-1) dw, respectively, excluding the limit of detection. At 83% of sites, concentrations were below 1000 pg g(-1) dw, whereas elevated levels were found at sites downstream of STP outfalls and in areas dominated by industrial and urban land-use types. Concentrations of PBDEs differed significantly (p=0.007) among sites according to predominant type of land-use. Significantly (p=0.02) higher SigmaPBDE concentrations were also present in estuarine compared to freshwater environments, while PBDEs were below the limit of detection at the marine site. At most sites, BDE-209 contributed the highest proportion to the SigmaPBDE concentrations. The exception was one site with an elevated concentration of BDE-183. Sampling and analytical variability were investigated as part of this study. Results showed generally satisfactory results for repeat analysis at a different laboratory and low variability among samples collected within 1000 m at low contaminated sites. However, at sites with elevated PBDE levels, sampling variability was high, with several fold to magnitudes of higher concentrations present among replicate sites. Corresponding to findings from elsewhere, these results demonstrate that urban and industrial activities provide the key input sources of PBDEs to the aquatic environment and provide a baseline for further investigation into the specific origin of contamination, as well as information on the background status of aquatic sediment contamination with PBDEs.