Placental transfer of the polybrominated diphenyl ethers BDE-47, BDE-99 and BDE-209 in a human placenta perfusion system: an experimental study

<p>Abstract</p> <p>Background</p> <p>Polybrominated diphenyl ethers (PBDEs) have been widely used as flame retardants in consumer products. PBDEs may affect thyroid hormone homeostasis, which can result in irreversible damage of cognitive performance, motor skills and altered behaviour. Thus, in utero exposure is of very high concern due to critical windows in fetal development.</p> <p>Methods</p> <p>A human ex vivo placenta perfusion system was used to study the kinetics and extent of the placental transfer of BDE-47, BDE-99 and BDE-209 during four-hour perfusions. The PBDEs were added to the maternal circulation and monitored in the maternal and fetal compartments. In addition, the perfused cotyledon, the surrounding placental tissue as well as pre-perfusion placental tissue and umbilical cord plasma were also analysed. The PBDE analysis included Soxhlet extraction, clean-up by adsorption chromatography and GC-MS analysis.</p> <p>Results and Discussion</p> <p>Placental transfer of BDE-47 was faster and more extensive than for BDE-99. The fetal-maternal ratios (FM-ratio) after four hours of perfusion were 0.47 and 0.25 for BDE-47 and BDE-99, respectively, while the indicative permeability coefficient (IPC) measured after 60 minutes of perfusion was 0.26 h^-1and 0.10 h^-1, respectively. The transport of BDE-209 seemed to be limited. These differences between the congeners may be related to the degree of bromination. Significant accumulation was observed for all congeners in the perfused cotyledon as well as in the surrounding placental tissue.</p> <p>Conclusion</p> <p>The transport of BDE-47 and BDE-99 indicates in utero exposure to these congeners. Although the transport of BDE-209 was limited, however, possible metabolic debromination may lead to products which are both more toxic and transportable. Our study demonstrates fetal exposure to PBDEs, which should be included in risk assessment of PBDE exposure of women of child-bearing age.</p

A retrospective study of PBDEs and PCBs in human milk from the Faroe Islands

BACKGROUND: Persistent organic pollutants (POPs) in wildlife and humans remain a cause of global concern, both in regard to traditional POPs, such as the polychlorinated biphenyls (PCBs), and emerging POPs, such as the polybrominated diphenyl ethers (PBDEs). To determine the time related concentrations, we analyzed human milk for these substances at three time points between 1987 and 1999. Polychlorobiphenylols (OH-PCBs), the dominating class of PCB metabolites, some of which are known to be strongly retained in human blood, were also included in the assessment. METHODS: We obtained milk from the Faroe Islands, where the population is exposed to POPs from their traditional diet (which may include pilot whale blubber). In addition to three pools, nine individual samples from the last time point were also analyzed. After cleanup, partitioning of neutral and acidic compounds, and separation of chemical classes, the analyses were carried out by gas chromatography and/or gas chromatography/mass spectrometry. RESULTS: Compared to other European populations, the human milk had high PCB concentrations, with pool concentrations of 2300 ng/g fat 1987, 1600 ng/g fat in 1994, and 1800 ng/g fat in 1999 (based on the sum of eleven major PCB congeners). The nine individual samples showed great variation in PCB concentrations. The OH-PCBs were present in trace amounts only, at levels of approximately 1% of the PCB concentrations. The PBDE concentrations showed a clear increase over time, and their concentrations in human milk from 1999 are among the highest reported so far from Europe, with results of individual samples ranging from 4.7 to 13 ng/g fat CONCLUSION: Although remote from pollution sources, the Faroe Islands show high concentrations of POPs in human milk, particularly PCBs, but also PBDEs. The PBDEs show increasing concentrations over time. The OH-PCB metabolites are poorly transferred to human milk, which likely is related to their acidic character

Environmental influences on reproductive health: the importance of chemical exposures

Chemical exposures during pregnancy can have a profound and life-long impact on human health. Due to the omnipresence of chemicals in our daily life, there is continuous contact with chemicals in food, water, air and consumer products. Consequently, human biomonitoring studies show that pregnant women around the globe are exposed to a variety of chemicals. In this review, we provide a summary of current data on maternal and fetal exposure as well as health consequences from these exposures. We review several chemical classes including polychlorinated biphenyls (PCBs), perfluoroalkyl substances (PFAS), polybrominated diphenyl ethers (PBDEs), phenols, phthalates, pesticides, and metals. Additionally, we discuss environmental disparities and vulnerable populations, and future research directions. We conclude by providing some recommendations for prevention of chemical exposure and its adverse reproductive health consequences

Konttialusten onnettomuusriskit ja turvallisuuden kehittäminen

Merikuljetukset ovat yksi merkittävimmistä logistisista toiminnoista ja Suomenkin ulkomaankaupasta noin 80 prosenttia kulkee meriteitse. Konttikuljetukset ovat mahdollistaneet tehokkaan ja sujuvan merikuljetusten muodon, mutta konttikuljetuksiin on viime aikoina yhdistetty paljon onnettomuusriskejä. Konttikuljetusten huima kasvu viimeisten vuosikymmenien aikana vaatii myös, että niiden turvallisuuteen kiinnitetään entistä enemmän huomiota. Tässä opinnäytetyössä tutkitaan konttialusten turvallisuuteen vaikuttavia tekijöitä. Tutkimuksen tavoitteena on selvittää, miten konttialusten turvallista kulkemista merellä voidaan kehittää. Tutkimuksessa etsitään keskeisiä syitä konttikuljetusten onnettomuuksiin merellä ja keinoja, miten onnettomuuksia voidaan ehkäistä. Teoreettinen viitekehys rakentuu merikuljetuksiin ja onnettomuuksien hallintaan liittyvästä kirjallisuudesta ja artikkeleista, sekä oppaista. Tutkimuksen teoreettinen viitekehys koostuu kahdesta eri osa-alueesta, joita ovat merikuljetukset ja onnettomuuksien hallinta. Ensimmäisessä osassa käsitellään merikuljetuksiin liittyvää lainsäädäntöä ja eri osapuolten vastuita, sekä konttikuljetuksien olennaisia osia. Toisessa osassa käsitellään konttikuljetuksiin liittyviä riskejä, lastiturvallisuutta ja vaarallisia aineita. Tutkimuksessa etsittiin syitä konttialusten onnettomuuksiin ja keinoja, miten niitä voidaan ehkäistä. Lisäksi selvitettiin, miten konttien sisältö vaikuttaa koko aluksen turvallisuuteen. Tutkimus toteutettiin laadullisena tutkimuksena, jonka tutkimusmenetelminä toimivat teemahaastattelut ja kirjallisuuskatsaus onnettomuustutkintaraportteihin. Tutkimuksen tulokset analysoitiin sisällönanalyysimenetelmin. Tutkimustulokset osoittivat, että konttialusten onnettomuuksista erityisesti tulipalot aluksilla aiheuttavat suuria onnettomuuksia, jotka voivat vahingoittaa vakavasti ihmishenkiä ja ympäristöä. Tutkimuksen tulosten mukaan suurimpia onnettomuusriskin aiheuttajia ovat kontin sisällön virheelliset ilmoitukset, lastiturvallisuuden laiminlyönti, ongelmat tiedonsiirrossa ja inhimilliset virheet yhdessä meriympäristön vaikutuksen kanssa. Konttialusten turvallisuutta voidaan kehittää tekemällä enemmän pistotarkastuksia kuljetettaviin kontteihin, jotta väärin lastatut ja ilmoittamatonta vaarallista ainetta kuljettavat kontit saadaan tunnistettua. Lisäksi turvallisuutta voidaan kehittää varmistamalla miehistön ja satamatyöntekijöiden ammattitaito. Lastiturvallisuuden tietouden lisääminen ja siitä huolehtiminen on myös avainasemassa onnettomuuksien ehkäisemisessä

Organohalogen contaminants in humans with emphasis on polybrominated diphenyl ethers

The occurrence and distribution of organohalogen compounds, including polybrominated diphenyl ethers (PBDEs), in humans was investigated. For this purpose, the previously used method for analysis of organochlorine compounds was modified for the analysis of PBDEs and hydroxylated metabolites of polychlorinated biphenyls (OH-PCBs) in breast milk, matemal and cord blood plasma, liver and adipose tissue. PBDEs and PCBs were found in all samples. The PCB levels were approximately 100 times higher than those of PBDEs. Among the PBDEs, 2,2',4,4'-tetraBDE (BDE-47) was the predominant congener in breast milk, adipose tissue, matemal and cord blood, while in liver samples 2,2',4,4',5pentaBDE (BDE-99) occurred at similar concentrations as BDE- 47. The PCB congener profile was similar in all samples. 2,2',4,4',5,5'-hexaCB (CB-153), 2,2',3,4,4',5'-hexaCB (CB-138) and 2,2',3,4,4',5,5'-heptaCB (CB-180) were the dominant congeners. OH-PCBs constituted 30-50% of the sum of PCBs in blood samples, 1-10% in liver and 0.03-0.4% in adipose tissue, while the levels of OH-PCBs in breast milk were inconsiderable. Matrix specific differences were observed in OHPCB congener distribution. 2,2',3,4',5,5',6-heptachloro-4-biphenylol (4-OH-CB187) and 2,2',3,4',5,5'-hexachloro-4- biphenylol (4-0H-CB146) were the most dominant congeners in blood samples, 2,2',3,4,4',5'-hexachloro-3'-biphenylol (3'-OH-CB138) and 2,2',3,3',4,5'-hexachloro-4'-biphenylol (4'OH-CB130) in liver, 3´-OH-CB138 and 2,3,3',4',5,5',6-heptachloro-4-biphenylol (4-OH-CB 193) in adipose tissue. The presence of PBDEs, PCBs and OH-PCBs in cord blood demonstrates that placenta is not an effective barrier for the transfer of these compounds to the foetus. consequently, infants are exposed to organohalogen compounds already before they are born and additionally later via breast milk. Due to the low levels, postnatal exposure to OH-PCBs via breast milk in the present study subjects was considered of a minor importance. Temporal trends in contaminants have been investigated by analysing breast milk from different time periods. The levels of oganochlorine compounds: PCBs polychlorinated naphtalenes, dibenzo-rho-dioxins, dibenzofurans and several pesticides decreased to different extent from 1972 to 1997. During the same time period increasing levels of PBDEs were found. However, from 1998 to 2000 a decrease in PBDE levels was observed. The change in the trend was mainly due to the decrease of the most dominant PBDE congener, BDE-47. No large difference was noticed in levels of higher brominated PBDEs. During the same time period the levels of organochlorine contaminants in breast milk continued to decrease