Higher Levels Of Hexachlorobenzene Research Articles

Cross-regional scale studies of organochlorine pesticides in air in China: Pollution characteristic, seasonal variation, and gas/particle partitioning

Few simultaneous studies of organochlorine pesticides (OCPs) in the atmosphere have been conducted across Southeast and Northeast China, and no data on the gas/particle (G/P) partitioning behaviors of several current-use OCPs are available. In this study, a one-year synchronous monitoring program was conducted for OCPs in Chinese atmosphere spanning 30° latitude and 60 °C temperature. A total of 111 pairs of gas and particle samples were collected from Mohe and Harbin in Northeast China and from Shenzhen in Southeast China. The detection frequency for 66.7 % of the OCPs exceeded 80 %, indicating their prevalence in the atmosphere. The concentrations of individual OCPs spanned six orders of magnitude, indicating different pollution levels. Highest levels of hexachlorobenzene were observed at all sites. Banned OCPs were found predominantly in secondary distribution patterns, whereas current-use OCPs were dominated by primary distribution patterns. In Harbin and Mohe, the concentrations of OCPs were highest in summer, followed by autumn and winter. No obvious seasonal variation was observed in Shenzhen associated with different cultivation types. At all three sites, OCPs were predominantly found in the gas phase, and higher percentages of particle-phase OCPs were observed in Harbin and Mohe than in Shenzhen. In this study, G/P partitioning models were used to study the G/P partitioning mechanism of OCPs. The Li–Ma–Yang model provided the most accurate prediction of the G/P partitioning behavior of OCPs with high molecular weights and low vapor pressures, particularly at low temperatures. However, OCPs with lower molecular weights and higher vapor pressures were predominantly in the equilibrium state, for which the Junge–Pankow model was suitable. This systematic cross-scale study provides new insights into pollution, G/P partitioning, and the environmental behavior of OCPs in the atmosphere.

Organochlorine pesticides and late life cognitive function: does race/ethnicity and sex matter?

AbstractBackgroundOrganochlorines (OCs) pesticides persist in the environment and body for extended periods. Little is known about their long‐term impact on cognition in later life. Some studies, have shown higher levels of selected OCs associated with lower cognitive function (CF). It remains unclear if the association differs among racial/ethnic groups or by sex.MethodUsing weighted linear generalized estimating equations, we explored whether the association between seven log‐transformed lipid‐adjusted OCs (ng/g) and CF is modified by race/ethnicity and sex in 985 adults, age 60+ from the National Health and Nutrition Examination Surveys (2011‐2014). Sample included: 57% females; 78.8% Non‐Hispanic (NH) White; 9.2% NH‐Black; 3.6% Mexican‐American; 4.1% Other‐Hispanic; 3.7% NH‐Asian; 0.5% Other Race/Ethnicity. A composite CF score was created using the mean of the z‐scores for word‐list memory test (CERAD W‐L) which included delayed recall and word list learning, animal fluency, and the Digit Symbol Substitution test (DSST). Covariates included age, education, marital status, sex, race/ethnicity. Sensitivity analysis included: BMI, Ratio of Income‐to‐Poverty (IPR) categorized in tertiles, and longest occupation held.ResultAdjusting for covariates, lower composite‐CF was associated with higher levels of p,p’‐DDT (p = 0.040). This remained significant after adjusting for BMI (p = 0.045), but not when accounting for IPR (p = 0.117) or longest held occupation (p = 0.083). For specific CF tests, beta‐hexachlorocyclohexane, hexachlorobenzene, mirex, oxychlordane, p’p‐DDE, p’p‐DDT, and trans‐nonachlor were all associated with lower scores on DSST (p‐range = 0.03‐0.001). None of the associations differed by race/ethnicity. But a few differed by sex. After sex‐stratification, lower DSST scores were associated with higher levels of hexachlorobenzene in women (p = 0.032], but not men (p = 0.242). In sensitivity analyses, hexachlorobenzene lost all statistical significance after adjusting for each additional variable. The association between mirex and DSST disappeared after adjusting for longest occupation (p = 0.068). All other specific‐OC associations remained significant after BMI, IPR and occupation adjustment (p<0.05).ConclusionHigher blood levels of some OCs were associated with lower CF among older adults, some particularly affecting women, suggesting there may be long term negative effects of these chemicals. Future exposure studies should focus on sex‐differences. These associations did not differ between races; thus future analyses should consider examining within race/ethnic differences.

Comparison by Race and Ethnicity of Endocrine Disrupting Chemical levels in the U.S. Military

BACKGROUND AND AIM: Prior studies reported racial/ethnic (R/E) differences in serum concentrations of polyhalogenated aromatic hydrocarbons (PHAHs), an endocrine disrupting chemical class including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), and organochlorine pesticides (OCPs). We investigated R/E differences in PHAH serum concentrations in members of the U.S. military. METHODS: Serum samples, obtained 1994-2010, for 742 active-duty military personnel were analyzed by ICP mass-spectrometry. We compared serum concentration levels of 14 PCBs, 4 PBDEs, 1 PBB, and 5 OCPs, for which at least 40% of samples had detectable values. We used a multiple imputation method to replace values below the detection limit. Age-adjusted geometric means (aaGMs) of serum concentrations (ng/g-lipid) of these analytes were compared by R/E between the 467 (66.0%) non-Hispanic (NH) whites (reference), 132 (18.6%) NH blacks, 68 (9.6%) Hispanics, and 41 Asians/Pacific Islanders (APIs) (5.8%) using generalized linear models. RESULTS:The mean participant age was 27.3 (SD=7.4) years. Compared to NH whites, NH blacks had higher aaGMs for all PCBs, while Hispanics had lower aaGMs. PBDE aaGMs were generally higher among NH blacks and Hispanics than NH whites; APIs also had lower levels. For OCPs, APIs had the highest levels of dichloro-diphenyl-trichloroethane (DDT). Yet, Hispanics had the highest levels of DDT’s major metabolite, dichlorodiphenyldichloroethylene (DDE). NH blacks had the highest levels of trans-nonachlor and oxychlordane, while NH whites had the highest levels of hexachlorobenzene. Most differences in aaGMs by R/E were statistically significant (p0.05). CONCLUSIONS:This study found differences in serum concentrations of several endocrine disrupting chemicals by R/E among military personnel. Studies are needed to investigate if these differences exist at entry into the military or are associated with military exposures. Disclaimer: The opinions here are the authors’ and do not reflect the official views of the Uniformed Services University or the Department of Defense. KEYWORDS: Endocrine disrupting chemicals, Pesticides, Chemical exposures, Occupational exposures

Atmospheric organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in the Antarctic marginal seas: Distribution, sources and transportation

From November 2013 to March 2014, air samples were collected in the Antarctic marginal seas during the 30th Chinese Antarctic research expedition. Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were analyzed in these samples. The mean concentrations were observed for hexachlorobenzene (HCB) >ΣPCBs >Σhexachlorocyclohexanes(HCHs) >Σdichlorodiphenyltrichloroethane(DDTs)>Σchlordanes. High levels of HCB were found near east Antarctica and in the Ross Sea, reflecting the re-emission of HCB from environmental reservoirs of these regions. Parent DDTs (p,p’- and o,p’-DDT) were rarely detected, suggesting that atmospheric DDT was predominantly influencedby weathered DDT from some secondarysources. However, fresh inputs of DDTs could not be excluded because there were still some samples with high proportions of parent DDTs. HCHs only were detected in the South Indian Ocean (near Australia), andthis result might be related to the intense emissions of HCHs from southern Australia. Ratios of trans-chlordane/cis-chlordanein most samples were lower than that in technical chlordane, reflecting the main influence of weathered chlordane. High levels of ΣPCBs were found in the Ross Sea, suggesting an intense re-emission of PCBs. Furthermore, atmospheric PCBs near the Antarctic Peninsula were also relatively high, this finding might be attributed to the emissions of PCBs from nearby Antarctic research stations. Comparing with the Arctic, transport of OCPs and PCBs towards Antarctica is more difficult. The Antarctic marginal seas would act as both barriers and “buffer zones”during the transportation processes.

Organochlorinated pesticides levels in a representative sample of the Spanish adult population: The Bioambient.es project.

Organochlorinated pesticides (OCPs) were measured in a representative sample of Spanish adults within the Bioambient.es project, a nationwide human biomonitoring program promoted by Spanish Ministry of Agriculture, Food and Environment. The objective of Bioambient.es is to establish reference levels of environmental pollutants in the general population. Participants were recruited in 2009-2010 during their annual medical examination at work. Serum levels of thirteen OCPs were investigated: Aldrin, endrin, dieldrin, heptachlor, heptachlor-epoxide, dichlorodiphenyldichloroethylenes (DDEs), hexachlorobenzene (HCB), dichlorodiphenyltrichloroethanes (DDTs) and hexachlorocyclohexanes (HCHs) The highest concentrations were observed for DDE, HCB and β-HCH. The 95th percentile, in ng/g lipids, were: 717.7 for 4,4-DDE, 160.4 for HCB and 107.2 for β-HCH, while concentrations of aldrin, endrin, heptachlor, α-HCH, 2,4-DDT, 4,4-DDT and 2,4-DDE were markedly lower and detected in less than 10% of the samples. Significant differences (p<0.05) were found for DDE and HCB and seasonality, gender and age. Analyzing the geographical distribution, participants from the north of Spain had highest levels of HCB while those from the center of Spain had highest levels of 4,4-DDE. Comparing to earlier studies, the results indicated a sharp decline in the OCP concentrations in the Spanish population over time, and today values are in the same range or lower than those reported in similar studies worldwide, except for HCHs and HCB that presented higher levels than in other European countries and much higher than those observed in US and Canada. This study represents the first nationwide survey of exposure to OCPs in Spain and provides a background reference range for exposure to OCPs in the Spanish adult occupied population. These results will allow establishing reference values, observing temporal trends and identifying high exposure groups.

Prenatal exposure to persistent organochlorine pollutants and female reproductive function in young adulthood

BackgroundThe biopersistent organochlorine pollutants dichlorodiphenyldichloroethylene (p,p′-DDE), hexachlorobenzene (HCB) and polychlorinated biphenyls (PCBs) can be detected in humans worldwide. The chemicals can cross the placenta and may interfere with endogenous hormonal homeostasis. ObjectivesTo investigate effects on female reproduction following intrauterine exposure to selected biopersistent organochlorines. MethodsWe used data from a Danish pregnancy cohort with follow-up on 436 eligible daughters at approximately 20years of age. Information on age of menarche (n=335), menstrual cycle length (n=230) and serum concentrations of reproductive hormones (n=243) was obtained. Number of antral follicles was counted by vaginal ultrasound (n=147). Of 244 daughters who attended clinical examination, 170 used hormonal contraceptives and 74 were non-users. Concentrations of p,p′-DDE, HCB and six PCB congeners were analysed in maternal serum samples obtained in pregnancy week 30. ResultsAge of menarche and menstrual cycle length were found not to be statistically significant associated with prenatal organochlorine exposure. Among non-users of hormonal contraceptives with information on antral follicle number (n=43), daughters exposed to the highest tertile of p,p′-DDE had 28% (95% confidence interval (95% CI): 5; 46%) lower follicle number compared to the low-level exposed reference group. Those exposed to medium and higher levels of HCB had 30% (95% CI: 5; 48%) and 28% (95% CI: 7; 44%) lower follicle number compared to the reference group. Furthermore, maternal serum HCB concentrations were inversely associated with free androgen index among non-users of hormonal contraceptives (n=73). These associations were not found in users of hormonal contraceptives. ConclusionsAmong non-users of hormonal contraceptives, we found indications of adverse long-term effects on female reproduction following prenatal exposure to biopersistent organochlorines. These findings may have wide implications for public health as intrauterine exposure occurs worldwide.

The effect of long-range atmospheric transport of organochlorine compounds by soil studies from Mongolia to the Arctic

The results of studies on the distribution regularities are presented for polychlorinated biphenyls (PCBs) of different degrees of chlorination and for organochlorine pesticides (OCPs): hexachlorobenzene (HCB), hexachlorocyclohexane (HCCH), and DDT with its metabolites in the soils along the Lena River valley and in background areas of Eastern Siberia and Mongolia. A statistically reliable correlation is found between the PCB–OCP and Corg concentrations. The highest levels of HCB are registered in the soils between 50 and 60° N. The concentrations of αand γ-HCCH increase reliably, while those of pp′-DDT and pp′-DDE decrease from south to north. A trend of the decrease in concentrations from Mongolia to the Laptev Sea is revealed for tri-, tetra-, and penta-chlorine-substituted PCB congeners. However, the soils sampled northwards from 60° N show a reliable increase in the concentrations of tetra-, penta-, and hexachlorine-substituted congeners.

Contamination and emission factors of PCDD/Fs, unintentional PCBs, HxCBz, PeCBz and polychlorophenols in chloranil in China

The production of chloranil is regarded as a potentially significant source of unintentional POPs. This research aimed to identify the contamination levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), hexachlorobenzene (HxCBz), pentachlorobenzene (PeCBz) and polychlorophenols in chloranil samples and identify the formation pathways. The toxicity equivalent (TEQ) values for PCDD/Fs in the chloranil samples ranged from 163 to 1 540 200 pg I-TEQ g −1, while the PCB TEQ values ranged from 1.9 to 3.3 pg WHO–TEQ g −1. High levels of HxCBz, PeCBz and polychlorophenols were also detected in the chloranil samples. The average emission factors were 522.2 mg I-TEQ t −1 (PCDD/Fs), 0.0026 mg WHO–TEQ t −1 (PCBs), 32.6 mg t −1 (HxCBz), and 136.6 mg t −1 (PeCBz). The PCDD/Fs and PCBs are thought to be formed from the polychlorophenols and polychlorobenzenes generated during the chloranil production process. Purification of the chloranil products can reduce the unintentional POPs releases and protect the environment.

Accumulation of environmental estrogens in adipose tissue of breast cancer patients

Although the estrogenic properties of numerous chloroorganic pesticides have been widely recognized, population studies do not give clear results indicating the link between the exposure to these compounds and breast cancer development. Because of the weak affinity of these pesticides to estrogen receptors, they probably act by affecting the expression of CYP genes encoding cytochromes P450 engaged in the metabolism of environmental as well as natural estrogens. To examine the possible correlation between environmental estrogen levels in adipose tissue and breast cancer stage, grade, receptor status and onset of the disease, adipose tissue was isolated from 54 breast cancer patients and 23 healthy individuals. Clinical characteristics were obtained from the medical records, while the information concerning exposure to environmental estrogens where obtained from questionnaires. The environmental estrogens were identified and quantified by GC-chromatography. The data was analyzed with the use of Student t-test and Spearman correlation. The levels of most environmental estrogens did not differ between the patients and the controls, except the β -HCH (β -hexachlorocyclohexane) level, which was higher in the patients than in the healthy individuals. Significantly higher levels of DDE (1,1-bis(4-chlorophenyl)-2,2-dichloroethene) and DDT (1,1,1-trichloro-2,2-bis(4-chlorophenol)ethane) (P < 0.05) were observed in the patients with late onset of the disease which was probably due to the time of exposure. Moreover, in the patients exposed to environmental estrogens, significantly higher concentrations of DDD (1,1-bis(4-chlorophenyl)-2,2-dichloroethane) were found (P < 0.05). We also evidenced that estrogen-independent cancer was more frequent in the patients exposed to numerous risk factors in which higher levels of HCB (hexachlorobenzene), γ -HCH (γ -hexachlorocyclohexane), DDD and DDT in adipose tissue were detected. Breast cancer development is probably related to the accumulation of DDT and its derivatives, but the effect appears only in older patients. We postulate that environmental estrogens acting together with other risk factors might influence the progress and exacerbate the prognosis of breast cancer.

Serum levels of organochlorine pesticides in healthy adults from five regions of Spain

The aim of this study was to measure of serum levels of p,p′-dichlorodiphenyl trichloroethane ( p,p′-DDT), p,p′-dichlorodiphenyl dichlorethylene ( p,p′-DDE), β-hexachlorocyclohexane (β-HCH), and hexachlorobenzene (HCB) in healthy adults in Spain. Furthermore, we also analyzed these levels according to dietary, other lifestyle factors and anthropometric characteristics. We measured the concentrations of such organochlorine pesticides (OCPs) in serum samples collected during 1992–1996 from 953 subjects aged 35–64 years, they were residents of five Spanish regions, they were randomly selected from the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. OCPs were determined by means of gas chromatography with electron-capture detection (GC-ECD). The most frequent compound found in serum was p,p′-DDE, present in 98% of the samples, followed by HCB and β-HCH, found in 89% and 77% of samples, respectively, while p,p′-DDT could be measured only in 26% of subjects. The geometric means of serum concentrations (ng/g lipid) were 822 for p,p′-DDE, 167 for β-HCH, and 379 for HCB. The concentrations of all OCPs were positively associated with age and body mass index, and decreased along the period of blood collection. No association was found between OCPs levels and dietary factors. The concentrations of p,p′-DDE and β-HCB were higher in Murcia, one of southern regions, most likely associated with intensive past use of pesticides related to agricultural practices, while higher levels of HCB were found in Navarra, located in the north, maybe due to industrial use rather than agricultural application.

Reproductive outcomes of maternal contamination with Cyclodiene insecticides, Hexachlorobenzene and β-Benzene Hexachloride

The effects of organochlorines on human reproduction have been recently under scrutiny. Some negative effects on animal reproduction have been reported. In this study we aimed to evaluate the effect of maternal contamination with a certain group of organochlorines, which are cyclodienes, HCB (hexachlorobenzene) and β-BHC (beta-hexachlorocyclohexane) on human reproduction. Breast milk samples from 815 eligible Victorian mothers were used for measuring maternal contamination and the reproductive outcomes such as birth weight, head circumference and prematurity were taken from health files.Our study did not show any significant negative effect on outcomes such as birth weight, small for gestation age, previous miscarriage or still birth, head circumference or sex ratio. An inconsistent increase across oxychlordane exposure levels for prematurity was found. We also found an inverse association between the highest levels of HCB and oxychlordane with previous miscarriage or still birth; but this was based on small numbers and may be explained by loss of contaminants through the aborted fetus. These results suggest that the declining contamination levels of these chemicals do not impose a threat to human reproduction.

Brominated flame retardants and organochlorine pollutants in aquatic and terrestrial predatory birds of Belgium: levels, patterns, tissue distribution and condition factors

Liver and muscle samples from 7 species of aquatic and terrestrial predatory birds from Flanders (Belgium) were analysed for polychlorinated biphenyls (PCBs), polybrominated diphenylethers (PBDEs) and organochlorine pesticides (OCPs). PCBs were the predominant compounds in our samples, which showed highest concentrations in the liver of barn owl ( Tyto alba) and sparrowhawk ( Accipiter nisus) (up to 1000 μg/g lipid weight). PBDEs could be determined in most samples at lower concentrations than PCBs (up to 64 μg/g lipid in sparrowhawk liver). Sparrowhawks had the highest levels of hexachlorobenzene, DDTs and PBDEs. In contrast, kestrels ( Falco tinnunculus) had relatively low levels of most measured organochlorines. BDE 47 was the most abundant congener in heron ( Ardea cinerea) and grebe ( Podiceps cristatus), while BDE 47, 99 and 153 were equally important in the terrestrial species. BDE 183 and BDE 209 were only measured in the terrestrial birds. These results indicate that terrestrial birds may be more exposed to higher brominated BDE congeners than aquatic species.

Disruption of androgen regulation in the prostate by the environmental contaminant hexachlorobenzene.

Hexachlorobenzene (HCB) is a persistent environmental contaminant that has the potential to interfere with steroid hormone regulation. The prostate requires precise control by androgens to regulate its growth and function. To determine if HCB impacts androgen action in the prostate, we used a number of methods. Our in vitro cell-culture-based assay used a firefly luciferase reporter gene driven by an androgen-responsive promoter. In the presence of dihydrotestosterone, low concentrations (0.5-5 nM) of HCB increased the androgen-responsive production of firefly luciferase and high concentrations of HCB (> 10 microM) suppressed this transcriptional activity. Results from a binding assay showed no evidence of affinity between HCB and the androgen receptor. We also tested HCB for in vivo effects using transgenic mice in which the transgene was a prostate-specific, androgen-responsive promoter upstream of a chloramphenicol acetyl transferase (CAT) reporter gene. In 4-week-old mice, the proportion of dilated prostate acini, a marker of sexual maturity, increased in the low HCB dose group and decreased in the high HCB dose mice. In the 8-week-old mice, there was a significant decrease in both CAT activity and prostate weight upon exposure to 20 mg/kg/day HCB. Therefore, in vitro and in vivo data suggest that HCB weakly agonizes androgen action, and consequently, low levels of HCB enhanced androgen action but high levels of HCB interfered. Environmental contaminants have been implicated in the rising incidence of prostate cancer, and insight into the mechanisms of endocrine disruption will help to clarify their role.

Association of hexachlorobenzene and other organochlorine compounds with anthropometric measures at birth.

The aim of the present study was to assess the association of prenatal exposure to hexachlorobenzene (HCB) and other organochlorine compounds with anthropometric measures at birth. A total of 98 mother-infant pairs (83% of all children born in a specific area polluted with HCB in the period 1997-1999) were recruited after giving written consent. Levels of organochlorine compounds were measured in 72 maternal serum samples at delivery and in 70 cord serum samples. Of the organochlorines measured in cord serum, median levels of HCB were higher than for the other compounds (median of HCB = 1.13 ng/mL, median of dichlorodiphenyl dichloroethylene = 0.85 ng/mL, and median of total polychlorinated biphenyls = 0.27 ng/mL). Premature newborns had higher concentrations of HCB [1.94 ng/mL among prematures versus 1.10 among nonprematures (p < 0.10)], dichlorodiphenyl dichloroethylene [2.40 versus 0.80 (p < 0.05)], and polychlorinated biphenyls in cord serum [0.70 versus 0.14 (p < 0.10)]. Those infants born with a small length for gestational age had higher levels of HCB in cord serum than those with an adequate length for gestational age [1.64 ng/mL versus 1.00 ng/mL (p < 0.05)]. In addition, HCB cord serum levels were negatively associated in a dose-response way with crown-heel length [for each doubling of the dose there was a decrease of 0.46 (SE = 0.22) cm] after adjusting for smoking, gestational age, and other organochlorine compounds. The associations of dichlorodiphenyl dichloroethylene and polychlorinated biphenyls with length were not significant. The results did not vary when stratified for prematurity. These data suggest that HCB reduces intrauterine physical linear growth.

Health effects of chronic high exposure to hexachlorobenzene in a general population sample.

Hexachlorobenzene, an organochlorine compound that accumulates in humans, is widespread throughout the environment. In this study, we describe the health status of inhabitants of a rural village that surrounds an electrochemical factory characterized by high levels of hexachlorobenzene in the air. During 1994, we conducted a cross-sectional study of 1 800 inhabitants in the south of Catalonia, Spain, who were older than 14 y of age. We obtained information on lifestyles and occupational and medical histories via questionnaire. Self-reported health outcomes were validated against clinical records and cancer registry data. Serum levels of hexachlorobenzene were very high in males who worked in the electrochemical factory (geometric mean = 54.6 ng/ml in randomized participants). Levels were lower among subjects who had never worked in the electrochemical factory (females, 14.9 ng/ml; males, 9.0 ng/ml). Levels of other organochlorine compounds (i.e., beta-hexachlorocy-clohexane, 2,2-bis[p-chlorophenyl]-1,1-dichloroethylene) were in the same range found in other communities. Perceived health, prevalence of self-reported common chronic conditions, and porphyria cutanea tarda, thyroid pathology, Parkinson's disease, cancer, and reproductive outcomes were within the ranges observed in other studies. Employment in the plant, however, was associated with having any of the a priori selected health outcomes that were potentially related to exposure to hexachlorobenzene (odds ratio for cancer prevalence = 1.9; 95% confidence interval = 0.5, 7.6). Our population of workers and nonworkers had the highest levels of hexachlorobenzene ever described. The results suggest that exposure to hexachlorobenzene did not affect the general health status of the this population, but it was associated with specific health effects of the most highly exposed subjects.

Soil flushing using colloidal gas aphron suspensions generated from a plant-based surfactant

Natural surfactant solutions obtained from the fruit pericarps of Sapindus mukorossi, commonly known as Ritha or soapnut, are tested for their ability to remove hydrophobic organic compounds (HOCs) from soil. Colloidal gas aphron (CGA) suspensions generated using the surfactant are used in this study to flush an HOC from a representative soil. Soil is spiked with a chlorinated hydrocarbon, hexachlorobenzene (HCB), serving as a model HOC representative of contamination at a Superfund site north of Baton Rouge, LA. The recovery of HCB from soil columns using CGA suspensions was considerably larger than that for a waterflood. HCB recoveries in the effluent reached a maximum by the fifth pore volume and remained fairly constant for soils contaminated with high levels of HCB. This maximum HCB concentration in the column effluent was proportional to HCB solubility in the corresponding surfactant solutions. Natural surfactant performed marginally better in the form of conventional solutions than CGA suspensions at similar concentration in recovering HCB. HCB removal increased with increasing surfactant concentration due to increased aqueous solubility. The pressure buildup across the soil column remained fairly low when natural surfactant was used at concentrations up to 1%. Alternating the flushing media between CGA and water neither enhanced the recovery of HCB nor changed the pressure buildup across the soil column.

Uptake of chlorohydrocarbons from soil by lipid-containing semipermeable membrane devices (SPMDs)

Chlorohydrocarbons (CHCs) were surveyed in contaminated lake shore soil in Central Finland with polyethylene membranes containing synthetic triolein (SPMDs). High levels of hexachlorobenzene (HCBz) and PCBs were found in a significant number of the SPMDs exposed 28 days to 35 soil sampling locations along the 350 meter long shoreline. Distributions of HCBz and PCBs were different as demonstrated by two maximas of HCBz and four maximas of PCBs observed. Soil was also analyzed at selected locations for concentrations of CHCs, organic carbon (OC) and moisture. Steady state environmental fate modeling and simple equilibrium partition estimates based on analytical results both gave the same steady state concentrations in SPMD lipid for HCBz and PCB congeners. This indicates that HCBz and PCB concentrations in soil did not change significantly during the 28 day exposure. Uptake rates from soil to SPMD lipid were estimated and found not to correlate with moisture or OC. Approximation of the total contamination at the bulk shore soil gave 4.2 kg for HCBz and 3.4 kg for sum of PCBs.

Directed transport of volatile organochlorine pollutants to polar regions: the effect on the contamination pattern of Antarctic seabirds

Polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB) were analyzed in preen oil from birds from Antarctica, Sub-Antarctica and Europe. Antarctic and Sub-Antarctic birds contained unexpected high levels of volatile PCB-congeners and HCB compared to birds from temperate areas. This shows that the so-called cold-condenser effect causes concentrations of volatile organochlorine pollutants in Antarctic top-predators that are higher than in animals in more moderate climates close to the source of these pollutants. Antarctic top predators can be regarded as an utmost sink for volatile persistent pollutants. The levels of HCB indicate that seabirds from Sub-Antarctic regions are at risk to effects of organochlorine pollutants. Also Antarctic birds are potentially at risk, because of the high levels of HCB in combination with their extreme variability in physiological condition throughout the breeding season. When assessing the environmental impact of a contaminant this global effect should be of concern.

Chlorinated hydrocarbons- (CHC) and PCDD/F-levels in sediments and breams (Abramis brama) from the river Elbe (contribution to the German Environmental Specimen Banking)

Chlorinated hydrocarbons have been determined in sediments and breams (Abramis brama) from different locations along the river Elbe, starting from the border to the Czech Republic down-stream up to Cumlosen (river km 470), near the frontier of the former German Democratic Republic. High levels of hexachlorobenzene (HCB) have been found in sediments. HCB, DDT-metabolites and octachlorostyrene (OCS) have been the most dominant compounds in bream, especially fish from eastern sampling sites have been heavily contaminated. Furthermore, sediments from 1991–1993 have been analysed to determine polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F). The CHC-burden of the river Elbe declines downstream, whereas the PCDD/F-content increases in that direction.

Determination of polychlorinated biphenyl levels in the serum of residents and in the homogenates of seafood from the New Bedford, Massachusetts, area: A comparison of exposure sources through pattern recognition techniques

We measured the residues of polychlorinated biphenyls (PCBs) in the serum of 23 residents of the New Bedford, Massachusetts, area and from two homogenates each of bluefish and lobsters from the same area. We used congener-specific and total Aroclor quantitative approaches, both of which involved gas chromatography with electron capture detection. Using gas chromatography mass spectrometry (electron ionization mode), we confirmed the presence of PCBs in the combined serum samples and in the aliquots of bluefish and lobsters. In measuring the PCB levels in serum, we found good agreement between the two electron capture detector approaches ( r ≥ 0.97) when the serum of specific congeners was compared to total Aroclor. We used univariate and multivariate quality control approaches to monitor these analyses. Analytical results for bluefish showed a better agreement between the two techniques than did those for lobsters; however, the small number of samples precluded any statistical comparison. We also measured levels of chlorinated pesticides in the serum samples of two groups of New Bedford residents, those with low PCB levels (< 15 ng/ml) and those with high PCB levels (≥ 15 ng/ml). We found that residents with high PCB levels also tended to have higher levels of hexachlorobenzene (HCB) and 1,1-dichloro-2,2-di-( p-chlorophenyl) ethylene ( p, p′-DDE). The higher concentration of all three analyses appears to be influenced by employment in the capacitor industry, by seafood consumption, or both. Using Jaccard measures of similarity and principal component analysis we compared the gas chromatographic patterns of PCBs found in the serum of New Bedford area residents with high serum PCBs with the patterns found in homogenates of lobsters (inclusive of all edible portions except the roe), in homogenates of bluefish fillets taken from local waters, and in serum from goats fed selected technical Aroclors (e.g. Aroclors 1016, 1242, 1254, or 1260). The patterns found in human serum samples were similar to the patterns found in lobster homogenates. Both of these patterns closely resembled patterns found in the serum samples of the goat fed aroclor 1254, as demonstrated by both pattern recognition techniques. In addition, the chromatographic patterns of human serum and of lobsters and bluefish homogenates all indicated the presence of PCBs more characteristic of Aroclors 1016 or 1242.