Brominated and Chlorinated Flame Retardants in Tree Bark from Around the Globe

Brominated and chlorinated flame retardants were measured in about 40 samples of tree bark from 12 locations around the globe. The analytes were polybrominated diphenyl ethers (PBDE), Dechlorane Plus (DP), decabromodiphenylethane (DBDPE), hexabromocyclododecane (HBCD), hexabromobenzene (HBB), pentabromoethylbenzene (PBEB), pentabromobenzene (PBBz), and tetrabromo-<i>p</i>-xylene (pTBX). The highest concentrations of these compounds were detected at an urban site in Downsview, Ontario, Canada. Total PBDE and DP concentrations ranged from 2.1 to 190 ng/g lipid weight and from 0.89 to 48 ng/g lipid weight, respectively. Relatively high levels of DP (46 ± 4 ng/g lipid weight) were found at a remote site at Bukit Kototabang in Indonesia. The concentrations of total PBDE, DP, PBEB, and HBCD in the tree bark samples were significantly associated with human population in the nearby areas (<i>r</i>² = 0.21–0.56; <i>P</i> < 0.05). In addition, the concentrations of total PBDE and DP were significantly associated (<i>r</i>² = 0.40–0.64; <i>P</i> < 0.05). with the corresponding atmospheric concentrations of these compounds over a concentration range of 2–3 orders of magnitude

Elevated Levels of Ultrashort- and Short-Chain Perfluoroalkyl Acids in US Homes and People

Per- and polyfluoroalkyl substances (PFAS) make up a large group of fluorinated organic compounds extensively used in consumer products and industrial applications. Perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), the two perfluoroalkyl acids (PFAAs) with 8 carbons in their structure, have been phased out on a global scale because of their high environmental persistence and toxicity. As a result, shorter-chain PFAAs with less than 8 carbons in their structure are being used as their replacements and are now widely detected in the environment, raising concerns about their effects on human health. In this study, 47 PFAAs and their precursors were measured in paired samples of dust and drinking water collected from residential homes in Indiana, United States, and in blood and urine samples collected from the residents of these homes. Ultrashort- (with 2 or 3 carbons [C2–C3]) and short-chain (with 4–7 carbons [C4–C7]) PFAAs were the most abundant in all four matrices and constituted on average 69–100% of the total PFAA concentrations. Specifically, trifluoroacetic acid (TFA, C2) and perfluoropropanoic acid (PFPrA, C3) were the predominant PFAAs in most of the samples. Significant positive correlations (n = 81; r = 0.23–0.42; p < 0.05) were found between TFA, perfluorobutanoic acid (PFBA, C4), and perfluoroheptanoic acid (PFHpA, C7) concentrations in dust or water and those in serum, suggesting dust ingestion and/or drinking water consumption as important exposure pathways for these compounds. This study demonstrates that ultrashort- and short-chain PFAAs are now abundant in the indoor environment and in humans and warrants further research on potential adverse health effects of these exposures

Revised Temporal Trends of Persistent Organic Pollutant Concentrations in Air around the Great Lakes

The concentrations of polychlorinated biphenyls, polycyclic aromatic hydrocarbons (PAH), and several chlorinated insecticides in air have been measured every 12 days since 1991 at several sites on the shores of the North American Great Lakes. We give here the geometric mean concentrations for each of these compounds for each year and at each site. In most cases, these concentrations have been measured in both the vapor and particle phases; if concentrations were available for both phases, the two concentrations were summed, and those data are presented here. Assuming a first-order rate model for these data, we have calculated the time it takes for the concentrations to decrease by half. For most compounds, the halving times are the same for the vapor phase and for the vapor and particle phase concentrations summed together. The halving times are generally not distinguishable among the sites. Overall, the observed halving times are 8–15 years, except for that of lindane, which is disappearing with a halving time of ∼4 years

Interstudy and Intrastudy Temporal Trends of Polychlorinated Biphenyl, Pesticide, and Polycyclic Aromatic Hydrocarbon Concentrations in Air and Precipitation at a Rural Site in Ontario

Polychlorinated biphenyl (PCB), organochlorine pesticide, and polycyclic aromatic hydrocarbon (PAH) concentrations were measured in air (in the vapor and particle phases) and in precipitation samples collected at Point Petre on the northeastern shore of Lake Ontario as a part of the Integrated Atmospheric Deposition Network. These data were measured in two separate studies, one running from 1992 to 2003 (inclusive) and the other from 1998 to 2011 (inclusive). Having these two independent studies is a direct way of measuring changes in atmospheric concentrations and comparing interstudy changes to intrastudy changes. The concentrations of almost all pesticides declined between the two studies with halving times of 3–6 years; the concentrations of PAHs and PCBs did not change much between the two studies. This suggests that there are continuing sources of PAHs and PCBs to the Great Lakes atmosphere. PAH concentrations were elevated in the winter when space heating consumes greater amounts of fuel and emits larger amounts of PAHs. Pesticide and PCB concentrations were elevated in the summer because of enhanced volatilization from terrestrial or aquatic surfaces during hot summer days. Although there were a few exceptions (notably lindane), in general, the data from the two study periods gave similar results

Air is Still Contaminated 40 Years after the Michigan Chemical Plant Disaster in St. Louis, Michigan

The Michigan Chemical (also known as Velsicol Chemical) plant located in St. Louis, Michigan operated from 1936–1978. During this time, the plant manufactured polybrominated biphenyls (PBBs), hexabromobenzene (HBB), 1,1,1-trichloro-2,2-<i>bis</i>(4-chlorophenyl) ethane (DDT), and <i>tris</i>(2,3-dibromopropyl) phosphate (TDBPP), among other products. Due to widespread PBB contamination of Michigan, the plant eventually became a Superfund site, and despite years of cleanup activities, many of the compounds can still be found in the local ecosystem. To investigate the current atmospheric levels and to determine their spatial distributions, we collected tree bark samples from around Michigan and measured the concentrations of these pollutants. For comparison, other organic pollutants, such as polybrominated diphenyl ethers (PBDEs) and organophosphate esters (OPEs), which were not manufactured at the Michigan Chemical plant, were also measured in the same tree bark samples. Our results show levels of PBBs, DDT, and HBB in tree bark collected within 10 km of the Velsicol Superfund site (43, 477, and 108 ng/g lipid wgt., respectively) are 1–2 orders of magnitude higher than at sites located more than 10 km from the site (0.36, 28, and 0.36 ng/g lipid wgt., respectively). Levels of PBDEs and OPEs did not depend on distance from St. Louis. This is the first study on the atmospheric distribution of these chemicals around the Superfund site

Halogenated Flame Retardants in Baby Food from the United States and from China and the Estimated Dietary Intakes by Infants

Three categories of baby food (formula, cereal, and puree) were bought from United States and Chinese stores in 2013 and analyzed for polybrominated diphenyl ethers (PBDEs) and related flame retardants. The primary goal of this project was to investigate whether there were differences in the levels of flame retardants between these two nations’ baby foods. The median concentrations of total PBDEs (sum of BDE-17, -28, -47, -49, -99, -100, -153, -183, and -209) were 21 and 36 pg/g fresh weight for the Unites States and Chinese baby foods, respectively. Among non-PBDE flame retardants, hexabromobenzene, Dechlorane Plus (DP), and decabromodiphenylethane were frequently detected (22–57%) with median concentrations of 1.6, 8.7, and 17 pg/g fresh weight for United States samples, and 1.3, 13, and 20 pg/g fresh weight for Chinese samples. In general, the flame retardant concentrations in the United States and Chinese samples were not statistically different, but very high DP concentrations were observed in one Chinese formula sample (4000 pg/g) and in one United States cereal sample (430 pg/g), possibly suggesting contamination of the raw materials or contamination during production of these two samples. A comparison of median estimated daily dietary intake rates of BDE-47, -99, and -153 with existing reference doses for neurodevelopmental toxicity and other existing criteria suggested no concerns for the consumption of these baby foods

Organophosphate and Halogenated Flame Retardants in Atmospheric Particles from a European Arctic Site

Levels of 13 organophosphate esters (OPEs) and 45 brominated and chlorinated flame retardants (BFRs) were measured in particle phase atmospheric samples collected at Longyearbyen on Svalbard in the European Arctic from September 2012 to May 2013. Total OPE (ΣOPEs) concentrations ranged from 33 to 1450 pg/m³, with the mean ΣOPE concentration of 430 ± 57 pg/m³. The nonchlorinated tri-<i>n</i>-butyl phosphate (TnBP) and 2-ethylhexyl-diphenyl phosphate (EHDPP) were the most abundant OPE congeners measured, and the sum of all nonchlorinated OPE concentrations comprised ∼75% of the ΣOPE concentrations. The most abundant chlorinated OPE was <i>tris</i>(1-chloro-2-propyl) phosphate (TCPP). Total BFR concentrations (ΣBFRs) were in the range of 3–77 pg/m³, with a mean concentration of 15 ± 3 pg/m³. 2-Ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB) and <i>bis</i>(2-ethylhexyl)­tetrabromophthalate (TBPH) were among the relatively abundant BFRs measured in these samples and comprised ∼46% and 17% of ΣBFR concentrations, respectively. Total PBDE (ΣPBDE) concentrations constituted ∼37% of ΣBFR concentrations on average and ranged from 1 to 31 pg/m³. The most abundant PBDE congener was BDE-209, which contributed 24% to ΣPBDE concentrations. Dechlorane Plus (DP) was detected in all of the samples, and ΣDP concentrations (<i>syn</i>- + <i>anti</i>-DP concentrations) ranged from 0.05 to 5 pg/m³. Overall, ΣOPE concentrations were 1–2 orders of magnitude higher than the ΣBFR concentrations

Spatial and Seasonal Distributions of Current Use Pesticides (CUPs) in the Atmospheric Particulate Phase in the Great Lakes Region

The authors analyzed spatial and seasonal variations of current use pesticides (CUPs) levels in the atmospheric particulate phase in the Great Lakes basin. Twenty-four hour air samples were collected at six sites (two urban, two rural, and two remote) in 2015. The concentrations of 15 CUPs, including nine pyrethroid insecticides, four herbicides, one organophosphate insecticide, and one fungicide, were measured. The total CUPs concentrations were higher at the urban sites (0.38–1760 pg/m³) than at the rural and remote sites (0.07–530 pg/m³). The most abundant CUPs were pyrethroid insecticides at the urban sites. The levels of the other CUPs did not vary much among the six sites, except at the most remote site at Eagle Harbor, where the levels were significantly lower. Chlorothalonil was the most frequently detected CUP, which was detected in more than 76% of the samples. The atmospheric concentrations of total pyrethroid insecticides and total herbicides were correlated with local human population and developed land use. Significantly higher concentrations of most CUPs were observed in the warmer months than in the colder months at all sites. In addition to agricultural applications, which occur during the warmer months, the CUPs atmospheric concentrations may also be influenced by nonagricultural activities and the urban development

High Levels of Organophosphate Flame Retardants in the Great Lakes Atmosphere

Levels of 12 organophosphate flame retardants (OPs) were measured in particle phase samples collected at five sites in the North American Great Lakes basin from March 2012 to December 2012 (inclusive). The target compounds were three chlorinated OPs [tris­(2-chloroethyl) phosphate (TCEP), tris­(1-chloro-2-propyl) phosphate (TCPP), and tris­(1,3-dichloro-2-propyl) phosphate (TDCPP)], three alkyl phosphates [tri-<i>n</i>-butyl phosphate (TnBP), tris­(butoxyethyl) phosphate (TBEP), and tris­(2-ethylhexyl) phosphate (TEHP)], and six aryl phosphates [triphenyl phosphate (TPP), tri-<i>o</i>-tolyl phosphate (TOTP), tri-<i>p</i>-tolyl phosphate (TPTP), tris­(3,5-dimethylphenyl) phosphate (TDMPP), tris­(2-isopropylphenyl) phosphate (TIPPP), and tris­(4-butylphenyl) phosphate (TBPP)]. Total OP (ΣOP) atmospheric concentrations ranged from 120 ± 18 to 2100 ± 400 pg/m³ at the five sites, with the higher ΣOP levels detected at Cleveland and Chicago. ΣOP concentrations at these urban sites were dominated by the chlorinated OPs (TCEP, TCPP, and TDCPP), with the sum of these three compounds comprising 51 ± 6 and 65 ± 12% of ΣOP concentrations at these two sites, respectively. Nonhalogenated OP compounds were major contributors to ΣOP concentrations at the remote sites, with the sum of all nine nonhalogenated OP concentrations comprising 70 ± 21 and 85 ± 13% of the ΣOP concentrations at Eagle Harbor and Sleeping Bear Dunes, respectively. On average, these ΣOP concentrations are about 2–3 orders of magnitude higher than the concentrations of brominated flame retardants in similar samples

Has the Phase-Out of PBDEs Affected Their Atmospheric Levels? Trends of PBDEs and Their Replacements in the Great Lakes Atmosphere

Air and precipitation samples were collected every 12 days at five sites near the North American Great Lakes from 2005 to 2011 (inclusive) by the Integrated Atmospheric Deposition Network (IADN). The concentrations of polybrominated diphenyl ethers (PBDEs) and selected alternative brominated flame retardants [pentabromoethyl benzene (PBEB), hexabromobenzene (HBB), 1,2-<i>bis</i>(2,4,6-tribromophenoxy)­ethane (TBE or BTBPE), decabromodiphenylethane (DBDPE), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB), and <i>bis</i>(2-ethylhexyl)-tetrabromo-phthalate (TBPH)] were measured in these samples. The concentrations of almost all of these flame retardants were related to the number of people within a 25 km radius of the sampling site, except for HBB, the concentrations of which were relatively high at Sturgeon Point, and PBEB, the concentrations of which were relatively high at Eagle Harbor. The temporal trends of all of these concentrations were variable. For example, BDE-47 vapor phase concentrations were increasing with doubling times of 5–10 years at Sturgeon Point, Sleeping Bear Dunes, and Eagle Harbor, but these concentrations were slowly decreasing in all phases at Chicago. The most consistent trend was for TBE, which showed concentrations that were unchanging or decreasing in all phases at all sites. TBPH concentrations in particles and HBB concentrations in precipitation were rapidly increasing at most sites with doubling times of ∼2 years. The concentrations of DBDPE and BDE-209 were strongly and positively correlated, and the concentrations of TBB and TBPH were also strongly and positively correlated. The concentrations of TBB plus TBPH (representing Firemaster 550) and BDE-47, 85, 99, 100, 153, plus 154 (representing the withdrawn penta-BDE commercial mixture) were also strongly and positively correlated. These positive relationships indicate that the replacement of the deca-BDE commercial product by DBDPE and the penta-BDE product by Firemaster 550 have not yet become evident in the Great Lakes’ atmospheric environment