Rossana Bossi

Levels and trends of poly- and perfluorinated compounds in the arctic environment.

Poly- and perfluorinated organic compounds (PFCs) are ubiquitous in the Arctic environment. Several modeling studies have been conducted in attempt to resolve the dominant transport pathway of PFCs to the arctic-atmospheric transport of precursors versus direct transport via ocean currents. These studies are generally limited by their focus on perfluorooctanoate (PFOA) fluxes to arctic seawater and thus far have only used fluorotelomer alcohols (FTOHs) and sulfonamide alcohols as inputs for volatile precursors. There have been many monitoring studies from the North American and European Arctic, however, almost nothing is known about PFC levels from the Russian Arctic. In general, there are very few measurements of PFCs from the abiotic environment. Atmospheric measurements show the widespread occurrence of PFC precursors, FTOHs and perfluorinated sulfonamide alcohols. Further, PFCAs and PFSAs have been detected on atmospheric particles. The detection of PFCAs and PFSAs in snow deposition is consistent with the volatile precursor transport hypothesis. There are very limited measurements of PFCs in seawater. PFOA is generally detected in the greatest concentrations. Additional seawater measurements are needed to validate existing model predications. The bulk of the monitoring efforts in biological samples have focused on the perfluorinated carboxylates (PFCAs) and sulfonates (PFSAs), although there are very few measurements of PFC precursors. The marine food web has been well studied, particularly the top predators. In contrast, freshwater and terrestrial ecosystems have been poorly studied. Studies show that in wildlife perfluorooctane sulfonate (PFOS) is generally measured in the highest concentration, followed by either perfluorononanoate (PFNA) or perfluoroundecanoate (PFUnA). However, some whale species show relatively high levels of perfluorooctane sulfonamide (PFOSA) and seabirds are typically characterized by high proportions of the C(11)-C(15) PFCAs. PFOA is generally infrequently detected and is present in low concentrations in arctic biota. Food web studies show high bioaccumulation in the upper trophic-level animals, although the mechanism of PFC biomagnification is not understood. Spatial trend studies show some differences between populations, although there are inconsistencies between PFC trends. The majority of temporal trend studies are from the Northern American Arctic and Greenland. Studies show generally increasing levels of PFCs from the 1970s, although some studies from the Canadian Arctic show recent declines in PFOS levels. In contrast, ringed seals and polar bears from Greenland continue to show increasing PFOS concentrations. The inconsistent temporal trends between regions may be representative of differences in emissions from source regions.

Atmospheric monitoring of organic pollutants in the Arctic under the Arctic Monitoring and Assessment Programme (AMAP): 1993-2006.

Continuous and comparable atmospheric monitoring programs to study the transport and occurrence of persistent organic pollutants (POPs) in the atmosphere of remote regions is essential to better understand the global movement of these chemicals and to evaluate the effectiveness of international control measures. Key results from four main Arctic research stations, Alert (Canada), Pallas (Finland), Storhofdi (Iceland) and Zeppelin (Svalbard/Norway), where long-term monitoring have been carried out since the early 1990s, are summarized. We have also included a discussion of main results from various Arctic satellite stations in Canada, Russia, US (Alaska) and Greenland which have been operational for shorter time periods. Using the Digital Filtration temporal trend development technique, it was found that while some POPs showed more or less consistent declines during the 1990s, this reduction is less apparent in recent years at some sites. In contrast, polybrominated diphenyl ethers (PBDEs) were still found to be increasing by 2005 at Alert with doubling times of 3.5 years in the case of deca-BDE. Levels and patterns of most POPs in Arctic air are also showing spatial variability, which is typically explained by differences in proximity to suspected key source regions and long-range atmospheric transport potentials. Furthermore, increase in worldwide usage of certain pesticides, e.g. chlorothalonil and quintozene, which are contaminated with hexachlorobenzene (HCB), may result in an increase in Arctic air concentration of HCB. The results combined also indicate that both temporal and spatial patterns of POPs in Arctic air may be affected by various processes driven by climate change, such as reduced ice cover, increasing seawater temperatures and an increase in biomass burning in boreal regions as exemplified by the data from the Zeppelin and Alert stations. Further research and continued air monitoring are needed to better understand these processes and its future impact on the Arctic environment.

Do perfluoroalkyl compounds impair human semen quality

Background Perfluoroalkyl acids (PFAAs) are found globally in wildlife and humans and are suspected to act as endocrine disruptors. There are no previous reports of PFAA levels in adult men from Denmark or of a possible association between semen quality and PFAA exposure. Objectives We investigated possible associations between PFAAs and testicular function. We hypothesized that higher PFAA levels would be associated with lower semen quality and lower testosterone levels. Methods We analyzed serum samples for levels of 10 different PFAAs and reproductive hormones and assessed semen quality in 105 Danish men from the general population (median age, 19 years). Results Considerable levels of perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorohexane sulfonic acid were found in all young men (medians of 24.5, 4.9, and 6.6 ng/mL, respectively). Men with high combined levels of PFOS and PFOA had a median of 6.2 million normal spermatozoa in their ejaculate in contrast to 15.5 million among men with low PFOS–PFOA (p = 0.030). In addition, we found nonsignificant trends with regard to lower sperm concentration, lower total sperm counts, and altered pituitary–gonadal hormones among men with high PFOS–PFOA levels. Conclusion High PFAA levels were associated with fewer normal sperm. Thus, high levels of PFAAs may contribute to the otherwise unexplained low semen quality often seen in young men. However, our findings need to be corroborated in larger studies.

Perfluorinated compounds are related to breast cancer risk in greenlandic inuit: A case control study

BackgroundBreast cancer (BC) is the most common cancer for women in the western world. From very few cases an extraordinary increase in BC was observed in the Inuit population of Greenland and Canada although still lower than in western populations. Previous data suggest that exposure to persistent organic pollutants (POPs) might contribute to the risk of BC. Rat studies showed that perfluorinated compounds (PFCs) cause significantly increase in mammary fibroadenomas. This study aimed at evaluating the association between serum levels of POPs/PFCs in Greenlandic Inuit BC cases and their controls, and whether the combined POP related effect on nuclear hormone receptors affect BC risk.MethodsThirty-one BC cases and 115 controls were sampled during 2000-2003 from various Greenlandic districts. The serum levels of POPs, PFCs, some metals and the combined serum POP related effect on estrogen- (ER), androgen- (AR) and Ah-receptor (AhR) transactivity were determined. Independent student t-test was used to compare the differences and the odds ratios were estimated by unconditional logistic regression models.ResultsWe observed for the very first time a significant association between serum PFC levels and the risk of BC. The BC cases also showed a significantly higher concentration of polychlorinated biphenyls at the highest quartile. Also for the combined serum POP induced agonistic AR transactivity significant association to BC risk was found, and cases elicited a higher frequency of samples with significant POP related hormone-like agonistic ER transactivity. The AhR toxic equivalent was lowest in cases.ConclusionsThe level of serum POPs, particularly PFCs, might be risk factors in the development of BC in Inuit. Hormone disruption by the combined serum POP related xenoestrogenic and xenoandrogenic activities may contribute to the risk of developing breast cancer in Inuit. Further investigations are needed to document these study conclusions.

Analysis of polar pesticides in rainwater in Denmark by liquid chromatography–tandem mass spectrometry

A new LC-MS-MS method for analysis of rainwater has been developed and validated for 53 pesticides, degradation products of pesticides and selected nitrophenols. The method was used to monitor the concentration of pesticides in rainwater at one location near Roskilde, Denmark from February 2000 to August 2000. Sampling was done in periods of up to 4 weeks using a cooled wet-only sampler. Water samples were extracted by solid-phase extraction on Oasis HLB columns. The analysis of the extracts was performed by LC-MS-MS with electrospray ionization. All samples were analysed in negative and in positive ionization mode, respectively for acidic and neutral compounds. All analyses were done in the selected reaction monitoring mode in order to obtain a better signal-to-noise ratio. The method has been validated for the following parameters: recovery, detection limit, uncertainty and linearity. Atrazine, terbuthylazine, isoproturon, mechlorprop and (2-methyl-4-chlorophenoxy)acetic acid were measured at concentrations above 0.100 microg/l, mainly during the period of agricultural use. Nitrophenols were measured at high concentrations all year with peaks in the cold season (February-March).

Increased micronuclei and bulky DNA adducts in cord blood after maternal exposures to traffic-related air pollution ☆

Exposure to traffic-related air pollution in urban environment is common and has been associated with adverse human health effects. In utero exposures that result in DNA damage may affect health later in life. Early effects of maternal and in utero exposures to traffic-related air pollution were assessed through the use of validated biomarkers in blood cells from mother-newborn pairs. A cross-sectional biomonitoring study with healthy pregnant women living in the Greater Copenhagen area, Denmark, was conducted. Bulky DNA adducts and micronuclei (MN) were measured in blood from 75 women and 69 umbilical cords, concurrently collected at the time of planned Caesarean section. Modeled residential traffic density, a proxy measure of traffic-related air pollution exposures, was validated by indoor levels of nitrogen dioxide and polycyclic aromatic hydrocarbons in 42 non-smoking homes. DNA adduct levels were similar and positively correlated in maternal and cord blood (1.40 vs. 1.37 n/10(8) nucleotides; r=0.99; p<0.01). Maternal MN frequencies were significantly associated with age (p<0.01), and higher than those of the newborns (7.0 vs. 3.2 MN per 1000 binucleated cells). Adduct levels were highest among mother-newborn pairs who lived near medium-traffic-density (>400-2500 vehicle km/24h; p<0.01) places. MN frequencies among newborns from women who lived at high-traffic-density homes (>2500 vehicle km/24h) were significantly increased (p=0.02). This trend remained after adjusting for potential confounders and effect modifiers. For the first time increased bulky DNA adducts and MN in cord blood after maternal exposures to traffic-related air pollution are found, demonstrating that these transplacental environmental exposures induce DNA damage in newborns. Given that increased DNA damage early in life indicate an increased risk for adverse health effects later in life, these findings justify intervention of pregnant women.

Temporal Trends of Hexabromocyclododecane, Polybrominated Diphenyl Ethers and Polychlorinated Biphenyls in Ringed Seals from East Greenland

Concentrations of hexabromocyclododecane (HBCD) were determined in a combination of archived and fresh blubber samples of juvenile ringed seals from East Greenland collected between 1986 and 2008. α-HBCD was the only diastereoisomer consistently above levels of quantification and showed a significant log-linear (exponential) increase from 2.0 to 8.7 ng/g lipid weight (median concentrations) with an annual rate of +6.1%. The concentrations were up to several orders of magnitude lower than those reported for marine mammals from industrialized areas. Previously presented time trends on polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) have been extended with new data for 2006 and 2008. ΣPBDE in juvenile seals was the only parameter with a slight upward trend, however, dependent on the low 1986 concentration. Removing this data point resulted in a downward trend, which also was found for adult seals with a time trend starting in 1994. ΣPCB decreased significantly in juvenile seals, again due to the 1986 value, while no trend was found for the adult animals. This indicates stagnating PCB concentrations at a relatively high level, in some cases possibly exceeding tolerable daily intake rates for seal blubber as traditional Arctic food items.

Trends of perfluorochemicals in Greenland ringed seals and polar bears: Indications of shifts to decreasing trends

Time-series of perfluorinated alkylated substances (PFASs) in East Greenland polar bears and East and West Greenland ringed seals were updated in order to deduce whether a response to the major reduction in perfluoroalkyl production in the early 2000s had occurred. Previous studies had documented an exponential increase of perfluorooctane sulphonate (PFOS) in liver tissue from both species. In the present study, PFOS was still the far most dominant compound constituting 92% (West Greenland ringed seals), 88% (East Greenland ringed seals) and 85% (East Greenland polar bears). The PFOS concentrations increased up to 2006 with doubling times of approximately 6 years for the ringed seal populations and 14 years in case of polar bears. Since then a rapid decrease has occurred with clearing half-lives of approximately 1, 2 and 4 years, respectively. In polar bears perfluorohexane sulphonate (PFHxS) and perfluorooctane sulphonamide (PFOSA) also showed decreasing trends in recent years as do perfluorodecanoic acid (PFDA) and perfluoroundecanoic acid (PFUnA). For the West Greenland ringed seal population perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), PFDA and PFUnA peaked in the mid 2000s, whereas PFNA, PFDA and PFUnA in the East Greenland population have been stable or increasing in recent years. The peak of PFASs in Greenland ringed seals and polar bears occurred at a later time than in Canadian seals and polar bears and considerably later than observed in seal species from more southern latitudes. We suggest that this could be explained by the distance to emission hot-spots and differences in long-range transport to the Arctic.

Temporal trends of Persistent Organic Pollutants (POPs) in arctic air: 20 years of monitoring under the Arctic Monitoring and Assessment Programme (AMAP) ☆

Temporal trends of Persistent Organic Pollutants (POPs) measured in Arctic air are essential in understanding long-range transport to remote regions and to evaluate the effectiveness of national and international chemical control initiatives, such as the Stockholm Convention (SC) on POPs. Long-term air monitoring of POPs is conducted under the Arctic Monitoring and Assessment Programme (AMAP) at four Arctic stations: Alert, Canada; Stórhöfði, Iceland; Zeppelin, Svalbard; and Pallas, Finland, since the 1990s using high volume air samplers. Temporal trends observed for POPs in Arctic air are summarized in this study. Most POPs listed for control under the SC, e.g. polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethanes (DDTs) and chlordanes, are declining slowly in Arctic air, reflecting the reduction of primary emissions during the last two decades and increasing importance of secondary emissions. Slow declining trends also signifies their persistence and slow degradation under the Arctic environment, such that they are still detectable after being banned for decades in many countries. Some POPs, e.g. hexachlorobenzene (HCB) and lighter PCBs, showed increasing trends at specific locations, which may be attributable to warming in the region and continued primary emissions at source. Polybrominated diphenyl ethers (PBDEs) do not decline in air at Canadas Alert station but are declining in European Arctic air, which may be due to influence of local sources at Alert and the much higher historical usage of PBDEs in North America. Arctic air samples are screened for chemicals of emerging concern to provide information regarding their environmental persistence (P) and long-range transport potential (LRTP), which are important criteria for classification as a POP under SC. The AMAP network provides consistent and comparable air monitoring data of POPs for trend development and acts as a bridge between national monitoring programs and SCs Global Monitoring Plan (GMP).

Determination of sulfonylurea degradation products in soil by liquid chromatography-ultraviolet detection followed by confirmatory liquid chromatography-tandem mass spectrometry

A method based on liquid extraction followed by sample enrichment on reversed-phase solid-phase extraction was developed for the extraction of five degradation products of four sulfonylurea herbicides (chlorsulfuron, metsulfuron-methyl, thifensulfuron-methyl and tribenuron-methyl) from soil. The compounds have been quantified by LC-UV and identified by tandem LC-MS with electrospray ionization or atmospheric pressure chemical ionization. The limits of detection for the five compounds were between 10 and 50 micrograms kg-1. The method has been applied to the extraction of soil samples after microbial degradation of sulfonylurea herbicides.