Determination of phenolic organohalogens in human serum from a Belgian population and assessment of parameters affecting the human contamination

Many in vitro or in vivo studies highlighted the potential deleterious effects of phenolic organohalogenated compounds (POHs) on the health, particularly on the thyroid system homeostasis, however few large scale human epidemiological studies have been carried out, especially in Europe. Further studies monitoring the human contamination by POHs, the sources of exposure and the influence of these compounds on thyroid health are still needed. Therefore we determined the concentrations of 16 POHs (pentachlorophenol (PCP), tetrabromobisphenol A (TBBPA), 4 bromophenols (BPs), 3 hydroxy-polybromodiphenylethers (OH-PBDEs) and 7 hydroxy-polychlorobiphenyls (OH-PCBs)) in serum from 274 people aged from 18 to 76years old living in Liege (Belgium) and the surrounding area. A questionnaire about their alimentary habits, life style and home environment was also administered to the volunteers. The predominant compound measured in the population was PCP (median concentration of 593.0pgmL^-1). 4-OH-CB 107, 4-OH-CB 146 and 4-OH-CB 187 were detected in all samples and contributed for 75% of the sum of OH-PCBs (ΣOH-PCBs). The median measured in our population for ΣOH-PCBs was 143.7pgmL^-1. TBBPA and 2,4,6-tribromophenol were detected in 31% and 63.8% of the samples respectively while the detection frequency observed for the other BPs and the OH-PBDEs was close to zero. We computed multivariate regression models in order to assess the influence of demographic and lifestyle parameters on the PCP and ΣOH-PCBs contamination levels. Significant correlation was found between the PCP concentration and sex, smoker status, sea fish consumption and level of education, although the model seemed to be a poor (R²=0.14) predictor of the PCP concentration. The model computed for ΣOH-PCBs was more explanatory (R²=0.61) and involved age, BMI and sea fish consumption. Finally, we assessed the parameters affecting the ΣOH-PCBs/ΣPCBs ratio. The model proposed involved age, BMI, smoker status and parent PCB level, and explained 41% of the variability of the ΣOH-PCBs/ΣPCBs ratio.

Bioaccumulation of hydroxylated polychlorinated biphenyls and pentachlorophenol in the serum of northern elephant seal pups (Mirounga angustirostris)

Northern elephant seals (NES) (Mirounga angustirostris) from the Año Nuevo State Reserve (CA, USA) were sampled at 1-, 4-, 7- and 10-week post-weaning. Concentrations of hydroxylated polychlorinated biphenyls (HO-PCBs) and their parent PCBs were measured in the serum of each individual. The ΣHO-PCB concentrations in the serum increased significantly between early and late fast (from 282 ± 20 to 529 ± 31 pg/mL). This increase might result from a mobilisation of HO-PCBs transferred from the mother during gestation and/or lactation and stored in the pup's liver. Food deprivation has been shown to exacerbate biotransformation capacities in mammals, birds and fish. The HO-penta-CBs was the predominant homologue group, followed by HO-hexa-CBs and HO-hepta-CBs. No preferential pathway for the metabolism of HO-PCBs (HO-direct insertion or NIH-shift of a chlorine atom) could be evidenced. The concentrations of pentachlorophenol (PCP) in the serum of weaned NES increased from 103 ± 7 pg/mL at early fast to 246 ± 41 pg/mL at late fast, which is within the range of PCP concentrations usually encountered in marine mammals.

Temporal trend and age-dependent serum concentration of phenolic organohalogen contaminants in Japanese men during 1989-2010

The temporal trend in serum concentrations of phenolic organohalogen contaminants (POCs) were investigated in two age groups of men from Kyoto, Japan, from 1989 to 2010. These concentrations and trends were compared with neutral contaminants including polychlorinated biphenyls (PCBs) and pesticides. Serum concentrations of pentachlorophenol (PenCP) and 4-hydroxy-PCB187 were age-dependent and decreased to approximately one-half during the two decades, whereas no contamination trends were observed for 2,4,6-tribromophenol (TriBP), tetrabromobisphenol A (TBBPA) and 6-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (6-OH-BDE47). 6-OH-BDE47 was found in all samples (up to 3000 pg/g wet weight), whereas TBBPA was detected in 17 of 60 serum samples (up to 950 pg/g wet weight). The concentrations of TriBP, TBBPA and 6-OH-BDE47 were not correlated to those of PenCP or 4-OH-PCB187 in either age group, suggesting the different kinetics on exposure routes and fate between these brominated and chlorinated POCs.

Biochemical study of retired pentachlorophenol workers with and without following dietary exposure to PCDD/Fs

PCDD/Fs are found as impurities in commercial pesticide sodium pentachlorophenol (Na-PCP) salt. We compared, using multivariate logistic regression analysis adjusted for confounding factors, serum PCDD/F levels and biochemical examinations of retired Na-PCP workers and other inhabitants living near a closed Na-PCP plant that discharged PCP-contaminated wastewater into a nearby pond in Tainan, Taiwan. In this cross-sectional study from October 2006 through May 2009, 1167 participants were divided into groups according to their occupational (retired Na-PCP plant workers versus other residents) and dietary exposure (eating polluted fish versus not eating polluted fish) to PCDD/Fs, and a general population from a large-scale survey. Serum PCDD/F levels were significantly different between these groups (range: from 22.9±10.0pg WHO(98)-TEQ(DF) g(-1) lipid in the general population to 109.6±94.5pg WHO(98)-TEQ(DF) g(-1) lipid in retired Na-PCP workers eating polluted seafood; P(trend)<0.001). Distinct patterns of PCDD/Fs congener profiles, showing a significantly higher proportion of 1,2,3,7,8-PeCDD, 1,2,3,6,7,8-HxDD, and less 2,3,4,6,7,8-HpCDF, OCDF, were also found among workers and residents with different serum PCDD/F levels versus the general population. After adjusting for confounding factors, glucose (adjusted odds ratio [AOR] 7.22 [95% CI: 4.04-12.90]), triglycerides (AOR 4.31 [95% CI: 2.57-7.22]), blood urea nitrogen (AOR 2.90 [95% CI: 1.58-5.33]), creatine (AOR 5.83 [95% CI: 1.12-30.30]) and total protein (AOR 3.74 [95% CI: 1.91-7.31]) levels in retired workers were significantly higher than in the reference group. Occupational exposure to PCDD/Fs is associated with biochemical abnormalities that may persist for years after serum PCDD/F levels have declined.

Predictors of PCP, OH-PCBs, PCBs and chlorinated pesticides in a general female Norwegian population

The aims of the current study were to assess plasma concentrations and predictors of halogenated phenolic compounds (HPCs), polychlorinated biphenyls (PCBs) and chlorinated pesticides in a representative group of postmenopausal Norwegian women (n=311, mean age: 56 years). In addition to delivering a blood sample, the participants had also filled out a detailed questionnaire regarding their current health status, use of medication and dietary habits, etc. The association between a large number of dietary variables, lifestyle factors and plasma concentration of organic pollutants were investigated using multivariate statistics. Within the current study group, p,p'-DDE (median: 903 ng/L w.w.) and pentachlorophenol (PCP, median: 711 ng/L w.w.) were the dominating compounds on a wet weight basis and were present in considerable higher concentrations than the PCBs, the hydroxylated PCBs (OH-PCBs) and the remaining chlorinated pesticides. Of the PCBs, PCB 153 was detected in highest concentrations, whereas 4-OH-PCB187 was present in highest concentration of the selected OH-PCBs. The ratio of ΣOH-PCB to ΣPCB varied between 0.06 and 0.77 ng/L and were significantly lower in individuals with higher ΣPCB concentration. PCP did not co-vary with the other contaminants, indicating a different route of exposure. No clear food cluster was positively associated with PCP exposure; however intake of marine food was negatively linked to PCP concentration and age and being a non-smoker were positive predictors of PCP. The other investigated contaminants co-varied and were positively associated with age, plasma concentrations of marine derived omega-3 fatty acids and a traditional Norwegian fish and bread based diet. The difference in contaminant concentration between high, medium and low consumers of total marine food were however marginal for the dominating PCBs and chlorinated pesticides. The current results indicate however that marine food in itself could be a source of some of the OH-PCBs, regardless of their PCB precursors. As PCP is one of the dominating organic contaminants within the general female Norwegian population, future research on human concentrations, exposure routes and potential health effects of PCP is encouraged. Continued monitoring of human OH-PCB levels should also be performed as they could be present at levels almost as high as the PCBs and they are expected to be more toxic than their mother substances.

Global trends and diversity in pentachlorophenol levels in the environment and in humans: a meta-analysis

Pentachlorophenol (PCP) was banned or restricted in many countries worldwide because of its adverse effects on the ecological environment and humans. However, the endocrine disrupting effects caused by low environmental PCP exposure levels has warranted more analysis. We reviewed 80 studies conducted in 21 countries and published between 1967 and 2010, using meta-regression analysis to examine the time trends and regional differences in PCP levels. The results suggested that in indoor air, bodies of water, freshwater sediments in western countries, invertebrates and freshwater vertebrates, PCP levels had declined over time, with half-lives ranging from 2.0 years to 11.1 years. However, in marine sediments/vertebrates and Chinese surface water/sediments, PCP levels increased over time. PCP levels in human blood and urine had decreased since the 1970s, with population half-lives of 3.6 years and 5.7 years, respectively. The intervals for global population blood and urine reference values decreased to 1.1-6.3 μg/L (2002-2008) and 2.5-7 μg/L (1995-2003), respectively. The possible thyroid disrupting effects and other health risks correlated with low environmental PCP exposure should be concerning. This study can help to ascertain the effects of the banning/restriction policy, providing data for cost-benefit analysis in policy-making and further control of health risks caused by low environmental exposure to PCP.

Changes in serum concentrations of polychlorinated biphenyls (PCBs), hydroxylated PCB metabolites and pentachlorophenol during pregnancy

We studied pregnancy-related changes in serum concentrations of five polychlorinated biphenyls (PCBs, CB 118, CB 138, CB 153, CB 156, CB 180), three hydroxylated PCB metabolites (4-OH-CB107, 4-OH-CB146, 4-OH-CB187), and pentachlorophenol (PCP). Median serum lipid content increased 2-fold between early (weeks 9-13) and late pregnancy (weeks 35-36) (N=10), whereas median PCB levels in serum lipids decreased 20-46%, suggesting a dilution of PCB concentrations in serum lipids. Nevertheless, strong positive intra-individual correlations (Spearman's r=0.61-0.99) were seen for PCBs during the whole study period. Thus, if samples have been collected within the same relative narrow time window during pregnancy, PCB results from one single sampling occasion can be used in assessment of relative differences in body burdens during the whole pregnancy period. Concentrations of OH-PCBs in blood serum tended to decline as pregnancy progressed, although among some women the concentrations increased at the end of pregnancy. Positive intra-individual correlations (r=0.66-0.99) between OH-PCB concentrations were observed during the first and second trimester, whereas correlations with third trimester concentrations were more diverging (r=-0.70-0.85). No decline in PCP concentrations was observed during pregnancy and no significant correlations were found between concentrations at different sampling periods. Our results suggest that for both OH-PCBs and PCP, sampling has to be more specifically timed depending on the time period during pregnancy that is of interest. The differences in patterns of intra- and inter-individual variability of the studied compounds may be due to a combination of factors, including lipid solubility, persistence of the compounds, distribution in blood, metabolic formation, and pregnancy-related changes in body composition and physiological processes.

Pentachlorobenzene, hexachlorobenzene, and pentachlorophenol in children's serum from industrial and rural populations after restricted use

The study of a population of 4-year-old children born between 1997 and 1999 in an urban area under strong inputs of pentachlorobenzene (PeCB) and hexachlorobenzene (HCB) suggested that the measured concentrations of pentachlorophenol (PCP) in serum may essentially result from metabolism of these chlorinated hydrocarbons. In contrast, examination of a rural population of children where the same compounds were present at relatively low levels points to other inputs besides transformation of PeCB and HCB being responsible for the measured PCP concentrations. In both populations, the results showed that a major proportion of the organochlorine compounds present in these children's serum at 4 years of age was incorporated during the lactation period.

Factors related to dioxin and furan body levels among Michigan workers

We evaluated serum concentrations of five selected dioxin, furan, and polychlorinated biphenyls (PCB) congeners among 412 workers at a Midland, Michigan plant that manufactured trichlorophenol and pentachlorophenol (PCP) and formulated chlorophenol-based products. We examined occupational indicators of exposure to these chlorophenols taking into account intrinsic factors such as age and body fat and potential environmental sources of exposure from consumption of local game and fish and other occupations. All five congeners were significantly associated with age and body fat. 2378-TCDD serum concentrations were associated with trichlorophenol operations, total years employed at the plant, as well as working as a hazardous waste worker. 123678-H(6)CDD serum concentrations were related to occupational PCP exposure, chloracne, recent weight loss, eating local game, and working as a hazardous waste worker. Serum concentrations of PCB126 were related to smoking (inversely), and eating local fish or local game. Other factors such as diet and jobs outside of the chlorophenol plant exposures had only a very minor impact on dioxin and furan concentrations in these workers.

Development of a solid phase microextraction-gas chromatography-mass spectrometry method for the determination of pentachlorophenol in human plasma using experimental design

A new method, headspace solid-phase microextraction (HS-SPME) with in situ derivatization and gas chromatography-mass spectrometry (GC-MS), which was used for the determination of trace amount of pentachlorophenol (PCP) in human plasma was presented. The acetylation derivatization reaction was firstly optimized using a Doehlert design. Then a series of parameters relevant to the headspace SPME procedure, including fiber coating, extraction temperature, extraction time and salt addition, were optimized using a two-level full factorial design expanded further to a central composite design. The validation of method showed that the optimized method had good linearity (R(2)=0.999) within the concentration ranges 0.1-50.0ngml(-1), and was sensitive with the limit of detection of 0.02ngml(-1). Intra- and inter-day precision for pentachlorophenol in human plasma samples were not greater than 11.9% and 12.6%, respectively. The proposed method, to our knowledge, describes the first application of HS-SPME with GC-MS for analysis of PCP in blood plasma sample. Application of the method to real human plasma samples, PCP was successfully detected in some cases at concentration levels 1.2-6.3ngml(-1).

Twenty years of the German Environmental Survey (GerES): Human biomonitoring – Temporal and spatial (West Germany/East Germany) differences in population exposure

The German Environmental Surveys (GerESs) are nationwide population studies, which have repeatedly been carried out in Germany since the mid-1980s. The subjects were representatively selected from the regional registration offices with regard to age, gender and community size. The first survey for adults (GerES I) was carried out in 1985/1986 (West Germany) followed by GerES IIa in 1990/1991 (West Germany) and GerES IIb in 1991/1992 (East Germany). In GerES II children were also included to some extent. In 1998, the third GerES for adults was conducted in both parts of Germany (GerES III). The current survey 2003/2006 (GerES IV) is focussing exclusively on children. A 1-year pilot study was conducted in 2001-2002 to collect information on parameters influencing the response rate and to test the suitability of the different instruments intended to be used for the main study. The main goal of the surveys is to analyse and document the extent, distribution and determinants of exposure to environmental pollutants of the German general population. Three main instruments of investigation were comprised in GerES: human biomonitoring (HBM), monitoring of the domestic environment, and collecting information on exposure pathways and living conditions via questionnaires. This paper is focussed on the general design of the GerESs, the trend over time and spatial differences (West Germany and East Germany) for HBM data on arsenic, cadmium, lead, mercury, pentachlorophenol (PCP), and polycyclic aromatic hydrocarbons (PAH). These substances have been determined in blood and/or morning urine of adults and children. All GerESs have been conducted in close connection with the National Health Interview and Examination Surveys performed by the Robert Koch-Institute, Berlin.

Residential and biological exposure assessment of chemicals from a wood treatment plant

This paper evaluates the results of contamination of residents and residential homes located in close proximity to a Wood Treatment Plant. The plant has produced treated wood products continuously since 1904. The principle chemicals used to treat the wood, which is primarily used for railroad ties (oblong objects laid perpendicular to the rails to act as a base for the tracks), are creosote and pentachlorophenol. For a number of years, the plant burned treated waste wood products containing creosote and pentachlorophenol. First the plant pressure impregnates the wood with creosote and pentachlorophenol, and then the wood is stacked on open ground to allow it to air dry. Chemicals from recently treated wood ties are allowed to evaporate into the air or drip onto the ground surrounding the stacked wood. Small drainage ditches carry the liquid wastes into larger water channels where eventually the waste streams are discharged into a river adjacent to the plant. The river serves as a source of drinking water for the nearby community. Prevailing wind patterns favor a drift of air emissions from the plant's boiler stack over the nearby community and its residents. Over the past few years, the town's residents have become increasingly concerned about their health status and have voiced concerns regarding multiple health problems (including cancer), possibly associated with plant discharges. The intention of this study is to examine a representative sample of the potentially affected residents and to evaluate their residential environment for the presence of dioxin and/or its congeners. Data obtained from EPA's Toxic Release Information (TRI) database revealed the plant routinely discharged creosote, pentachlorophenol, dioxin and dioxin-like compounds into the ambient air via fugitive air emissions and surface waste waters. Sampling of household dust and water sediment within and outside of residences within a 2-mile radius of the plant revealed the presence of significantly elevated levels of dioxins, principally octachlorodibenzo-p-dioxin (OCDD) and 1,2,3,4,6,7,8-hepta-CDD. Biomonitoring of 29 subjects identified the presence of significantly elevated chlorinated dioxins and furan levels (OCDD=1049 ppt for exposed and 374 ppt for controls and 1,2,3,4,6,7,8-hepta CDD=132 ppt for exposed and 45.1 ppt for controls). These levels are consistent with exposures to pentachlorophenol in this group of subjects. And they confirm the presence of unsafe levels of chlorinated dioxins in these persons.

Polychlorinated biphenyls and their hydroxylated metabolites (OH-PCBS) in pregnant women from eastern Slovakia

OBJECTIVE

Our aim in the present study was to characterize and quantify the levels of polychlorinated biphenyls (PCBs) and specific polychlorobiphenylol (OH-PCB) metabolites in maternal sera from women delivering in eastern Slovakia.

DESIGN

During 2002-2004, blood samples were collected from women delivering in two Slovak locations: Michalovce district, where PCBs were formerly manufactured, and Svidnik and Stropkov districts, about 70 km north.

PARTICIPANTS

A total of 762 and 341 pregnant women were sampled from Michalovce and Svidnik/Stropkov, respectively, and OH-PCBs were measured in 131 and 31. EVALUATION/MEASUREMENTS: We analyzed PCBs using gas chromatography (GC)/electron capture detection. OH-PCBs and pentachlorophenol (PCP) were determined as methyl derivatives using GC-electron capture negative ionization/mass spectrometry. We characterized distributions in the full cohort using inverse sampling weights.

RESULTS

The concentrations of both PCBs and OH-PCB metabolites of Michalovce mothers were about two times higher than those of the Svidnik/Stropkov mothers (p < 0.001). The median weighted maternal serum levels of the sum of PCBs (sigmaPCBs) were 5.73 ng/g wet weight (Michalovce) and 2.82 ng/g wet weight (Svidnik/Stropkov). The median sum of OH-PCBs (ZOH-PCBs) was 0.55 ng/g wet weight in Michalovce mothers and 0.32 ng/g wet weight in Svidnik/Stropkov mothers. 4-OH-2,2',3,4',5,5',6-Heptachlorobiphenyl (4-OH-CB187) was a primary metabolite, followed by 4-OH-2,2',3,4',5,5'-hexachlorobiphenyl (4-OH-CB146). Only four PCB congeners-CBs 153, 138, 180, and 170--had higher concentrations than 4-OH-CB187 and 4-OH-CB146 (p < 0.001). The median ratio of the sigmaOH-PCBs to the sigmaPCBs was 0.10.

CONCLUSIONS

Mothers residing in eastern Slovakia are still highly exposed to PCBs, and their body burdens of these pollutants and OH-PCB metabolites may pose a risk for adverse effects on health for themselves and their children.

Concentrations of polybrominated diphenyl ethers, polychlonnated biphenyls, and polychlorobiphenylols in serum from pregnant Faroese women and their children 7 years later

The objective of this study was to assess blood concentrations of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs), and their polychlorobiphenylol (OH-PCB) metabolites in humans with a high seafood intake. Samples were obtained from pregnant women in the Faroe Islands in 1994-1995 and from their children at 7 years of age to examine maternal transfer of the compounds to their child, age-dependent metabolism, and temporal changes. Maternal serum was dominated by 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), while 2,2',4,4',5,5'-hexabromodiphenyl ether (BDE-153) prevailed in the children's serum seven years later. DecaBDE was present in both mothers and children up to 3 and 6 ng/g lipid weight, respectively. The sigmaPCB concentration in the children averaged about 60% of the concentrations in their mothers, with median levels for both above 1 microg/g lipid weight and .with similar PCB congener patterns. sigmaOH-PCB serum concentrations from the mothers and their children showed ranges of 1.8-36 ng/g wet weight (ww) and 0.49-22 ng/g ww, respectively, with all OH-PCB congener concentrations being lower in the children, except for 2,3,3',4',5-pentachloro-4-biphenylol (4-OH-CB107). Children at 7 years of age are exposed to PCBs at levels only slightly below those of their mothers, and the increased 4-OH-CB107 concentrations in children could be due to age-related differences in PCB metabolism. The PBDE concentrations were similar in both mothers and their children. The main persistent organic pollutant concentrations in the children are most probably due to other environmental exposure than maternal transfer.

Determination of Hydroxylated Polychlorinated Biphenyls (HO-PCBs)in Blood Plasma by High-Performance Liquid Chromatography-Electrospray Ionization-Tandem Quadrupole Mass Spectrometry

Hydroxylated metabolites of polychlorinated biphenyls (HO-PCBs) and pentachlorophenol (PCP) are halogenated phenolic compounds, and they are increasingly common as environmental contaminants mainly in the blood of wildlife and humans. A methodology based on high-performance liquid chromatography (reversed-phase)-electrospray (negative) ionization-tandem quadrupole mass spectrometry (LC-ESI(-)-MS-MS) in the select ion monitoring or multiple reaction monitoring modes was developed for HO-PCB and PCP determination in blood plasma and serum. Among 11 environmentally relevant HO-PCB congeners and PCP spiked to fetal calf serum, quantitative assessments, including matrix effects on ESI(-) suppression/ enhancement, showed process (recovery) efficiencies of 73% to 89% without internal standard (IS) correction, and 88% to 103% with IS correction, and method limits of quantification ranging from 1 to 50 pg/g (wet weight). Using the developed LC-ESI(-)-MS methodology in comparison with GC-MS and GC-ECD based approaches, similar results were found for HO-PCB identification and quantification in the plasma of polar bear (Ursus maritimus) from the Canadian arctic. LC-ESI(-)-MS identified four HO-PCB congeners [4'-HO-2,2',4,6,6'-pentachlorobiphenyl (4'-HO-CB104), 4-HO-2,3,3',4',5-pentachlorobiphenyl (4-HO-CB107), 4-HO-2,3,3',5,5',6-hexachlorobiphenyl (4-HO-CB165) and 3'-HO-2,2',3,4,4',5,5'-heptachlorobiphenyl (3'-HO-CB180)], and 14 additional tetra- to hepta-chlorinated HO-PCBs isomers in the polar bear plasma.

Current internal exposure to pesticides in children and adolescents in Germany: blood plasma levels of pentachlorophenol (PCP), lindane (gamma-HCH), and dichloro(diphenyl)ethylene (DDE), a biostable metabolite of dichloro(diphenyl)trichloroethane (DDT)

Pesticides are widely used throughout the world in agriculture to protect crops, and in public health to control diseases transmitted by animal vectors or intermediate hosts. After the prohibition of organochlorines such as DDT internal exposure of the general population to the organochlorines has been reduced markedly. Herein, current internal exposure of children and adolescents in an urban area in Germany to PCP, lindane, and DDT/E is reported. One hundred and thirty children and adolescents took part in this voluntary investigation. All of them stated they had never used pesticides in their homes or for medical reasons. Blood plasma was analysed for pentachlorophenol (PCP), lindane (gamma-HCH), and dichloro(diphenyl)ethylene (DDE), a biostable metabolite of dichloro(diphenyl)trichloroethane (DDT), using gas chromatography/electron capture detection according to well established methods approved by the Deutsche Forschungsgemeinschaft. Median (and 95th percentiles) in the age groups < 6, 6- < 12, and 12- < 18 years of age were (microgram/l): DDE: 0.75 (4.45), 0.95 (5.04), 0.89 (8.77); DDT: < 0.1 (0.22), < 0.1 (0.25), < 0.1 (0.30); PCP: 2.48 (17.32), 2.69 (5.85), 2.08 (8.04); lindane: < 0.1 (0.12, < 0.1 (0.08), < 0.1 (0.09). High levels of internal exposure to DDT in two girls were probably obtained during a holiday stay in India; high PCP-levels in two other girls were caused by a leather jacket impregnated with PCP, and a holiday abroad, respectively. Current background levels of internal exposure to organochlorine insecticides in children and adolescents in Germany are quantified. Exposure to these substances in the general population is thought to occur mainly via residues in food, which are low in general, today. In special cases, however, individual exposures may be dominated by other sources, i.e. impregnated leather clothes.

Human prenatal and postnatal exposure to polybrominated diphenyl ethers, polychlorinated biphenyls, polychlorobiphenylols, and pentachlorophenol

The aim of this study was to determine human prenatal and postnatal exposures to polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), hydroxylated metabolites of PCBs (polychlorobiphenylols; OH-PCBs), and pentachlorophenol (PCP). The median PBDE fresh-weight concentrations in maternal and cord blood plasma and in breast milk were 24, 4.3, and 75 pg/g, respectively. The PCB concentrations were approximately 60 times higher in each compartment (1,560, 277, and 4,310 pg/g, respectively). Calculated on a lipid weight basis, the levels were comparable in maternal blood plasma and breast milk. In contrast to PCBs, differences were found between PBDE congener distribution in maternal and cord blood plasma. The OH-PCBs constituted up to 26% of the PCB levels in maternal blood plasma and 53% in cord blood plasma, with levels of 120 and 88 pg/g fresh weight, respectively, and in breast milk 3 pg/g. The corresponding concentrations for PCP were 2,830, 1,960, and 20 pg/g. The ratios of PCB to OH-PCB were 13, 3, and 1,400 in maternal, cord plasma, and breast milk, respectively. It is evident that prenatal exposures occur for all the analytes. Moreover, the exposure continues after birth via breast milk. However, levels of OH-PCBs and PCP in breast milk are low compared with levels in blood plasma. Exposures to both PCBs and PBDEs, and in particular to the endocrine-active halogenated phenolic compounds, are of concern and implicate a potential risk for developmental disturbances.

Exposure assessment of residents living near a wood treatment plant

We report the results of environmental sampling and modeling in a neighborhood adjacent to a wood processing plant. This plant used creosote and pentachlorophenol (PCP) to treat wood for over 70 years. Between 1999 and 2001, environmental samples were obtained to quantify the level of environmental contamination from the wood processing plant. Blood from 10 residents was measured for chlorinated dioxins and dibenzofurans. Soil sediment samples from drainage ditches and attic/dust samples from nearby residents' homes were tested for polychlorinated dioxins, furans, and polycyclic aromatic hydrocarbons (PAH). The dioxin congeners analysis of the 10 residents revealed elevated valued for octachlorodibenzo-p-dioxin and heptachlorodibenzo-p-dioxin compatible with PCP as the source. The levels of carcinogenic PAHs were higher than background levels and were similar to soil contamination on wood preserving sites. Wipe sampling in the kitchens of 11 homes revealed that 20 of the 33 samples were positive for octachlorinated dioxins with a mean value of 10.27 ng/m2. The soil, ditch samples, and positive wipe samples from the homes indicate a possible ongoing route of exposure to the contaminants in the homes of these residents. Modeled air exposure estimated for the wood processing waste chemicals indicate some air exposure to combustion products. The estimated air levels for benzo(a)pyrene and tetrachlorodibenzodiozin in this neighborhood exceeded the recommended levels for these compounds in some states. The quantitative data presented suggest a significant contamination of a neighborhood by wood processing waste chemicals. These findings suggest the need for more stringent regulations on waste discharges from wood treatment plants.

Predictive value of human biomonitoring in environmental medicine: experiences at the outpatient unit of environmental medicine (UEM) of the University Hospital Aachen, Germany

There is little data on the distribution of biomonitoring parameters in patients at outpatient Units of Environmental Medicine (UEM). We evaluated the biomonitoring parameters of 646 UEM outpatients from our University Hospital 1988-1998. Few patients were exposed to specific substances. Data of patients who were not obviously exposed was analysed statistically (geometric mean, standard deviation, median, 95th percentile). Results were compared with reference values in literature. Normal distribution of biomonitoring parameters was rare. 95th percentiles for arsenic, chromium, selenium, zinc, phenol and toluene were below standard, 95th percentiles for copper and mercury above, and 95th percentiles for lead, cadmium, pentachlorophenol, lindane, and beta-hexachlorocyclohexane were within the published range of reference values. Thallium as well as most volatile organic compounds analyzed were below detection levels. Aluminum and fluorine exposure was rarely analysed. In view of these results, it is concluded that the indication for biomonitoring needs to be stringent as levels of biomonitoring parameters are generally not risen in patients of the UEM.

Association of elevated blood levels of pentachlorophenol (PCP) with cellular and humoral immunodeficiencies

It has long been suspected that pentachlorophenol (PCP) exerts a damaging influence on the immune system. In this study, the possible relationship between blood levels of PCP and immune function was studied in 190 patients who had been exposed for more than 6 mo to PCP-containing pesticides. The patients suffered from frequent respiratory infections and general fatigue. Lymphocyte subpopulations, in-vitro responses to mitogens, allogeneic stimulator cells, plasma neopterin, cytokines, soluble cytokine receptors, soluble adhesion molecules, and immunoglobulin autoantibodies were determined. A dose-response relationship between blood levels of PCP and cellular and humoral immune parameters was established. Blood levels of PCP were associated negatively with (a) total lymphocyte counts (p = .0002), CD4/CD8 ratios (p = .0015), and absolute counts of CD3+ (p < .0001), CD4+ (p < .0001), CD16+ (p < .0001), CD25+ (p = .0003), DR+ (p < .0001), CD8+/56+ (p = .020), and CD19+ cells (p = .092); (b) plasma levels of interleukin-2 (IL-2) (p < .0001), soluble IL-2R (p < .0001), IL-6 (p < .0001), IL-10 (p = .0039), interferon-gamma (IFN-gamma) (p < .0001), tumor necrosis factor-alpha (TNF-alpha) (p < .0001), transforming-growth factor-beta2 (p = .023), soluble IL-1 receptor antagonist (sIL-1 RA) (p < .0001), soluble intercellular adhesion molecule-1 (p = .0003); and (c) immunoglobulin (Ig) M-anti-Fab type autoantibodies (p = .0353). PCP levels were associated positively with (a) number of impaired stimulation assays per patient (p = .041); (b) number of circulating CD11b+ monocytes (p = .0015); and (c) plasma levels of neopterin (p < .0001), IL-4 (p = .020), and sIL-6R (p = .020). Compared with patients who had PCP plasma levels that were less than or equal to 10 microg/l, patients with blood levels of PCP that exceeded 10 microg/l experienced the following more often: low numbers of total blood lymphocytes (p = .054), CD3+ (p = .0014), CD4+ (p = .0001), DR+ (p = .0003), CD16+ (p = .0033), and CD25+ cells (p = .0033). In addition, the same aforementioned patients experienced the following more frequently: undetectable plasma levels of IL-2 (p = .0057), IL-6 (p = .042), IL-8 (p = .038), IL-10 (p = .0001), TNF-alpha (p = .0062), and IFN-gamma (p = .016); and impaired in-vitro responses of lymphocytes (p = .071). The authors concluded that increased blood levels of PCP were associated significantly with cellular and humoral immunodeficiencies. Recurrent respiratory infections and general fatigue could originate from PCP-associated immunosuppression.

PCP in the blood plasma: current exposure of the population in Germany, based on data obtained in 1998

The fungicidal substance pentachlorophenol (PCP) had been used commonly for wood protection and leather impregnation in Germany until 1989, when this substance was prohibited by law. Hence, the body burden in the general population in Germany has been steadily declining. The reference values (95th percentiles) in blood plasma decreased from 20 micrograms PCP/l in 1991 to 12 micrograms/l in 1996. In 1998 the current exposure in a large residential population was investigated. 623 persons with an average age of 34.6 years (0-62 years) were investigated. For all of them there was neither evidence of occupational contact with PCP nor of the presence of PCP in the residential indoor environment. The mean PCP concentration in the plasma samples was 2.4 +/- 3.9 micrograms/l, the median 1.7 micrograms/l, and the 95th percentile 6.1 micrograms/l, the maximum value was 59.3 micrograms/l. In children and adolescents higher median and 95th percentiles were obtained than in adults (median 2.5 vs. 1.5 micrograms/l and 95th percentile 7.7 vs. 5.9 micrograms/l). All values above 20 micrograms/l were checked again individually: relationships with the level of PCP in household dust could not be detected. In one family leather clothing containing PCP, however, was found to be the cause of unusually high PCP values in the blood. Our investigations confirm a trend observed in recent years: exposure to PCP in the population in Germany decreases steadily and leads to an actualized reference value of 6.1 micrograms PCP/l plasma. In individual cases, however, greatly increased PCP levels in blood can still occur today, for example due to leather clothing treated with PCP.

Long-term exposure to wood-preserving chemicals containing pentachlorophenol and lindane is related to neurobehavioral performance in women

BACKGROUND

The adverse neurobehavioral effects of long-term low exposure to wood-preserving chemicals (WPC) containing solvents, pentachlorophenol (PCP) and gamma-hexachlorocyclohexane (gamma-HCH; lindane), and other neurotoxicants were investigated in a neuropsychological group study.

METHODS

Out of a population of 2,000 women visiting the outpatient practice of a gynecological department, a sample of 15 women aged 31-56 (mean 43) with long-term exposure to WPC verified by self-report, biological monitoring, and environmental samples was investigated. Fifteen controls aged 42 (31-56) years were drawn from the same population and pair-wise matched with respect to sex, age, education, and estimated intelligence.

RESULTS

For the exposed group, mean PCP serum level was 43.6 micrograms/l and mean gamma-HCH blood level was 0.085 microgram/l. Mean duration of exposure was 10 (5-17) years. Intellectual functioning, attention, memory, and visuo-motor performance were examined, suggesting significant group differences in visual short-term memory (Benton Test; d = 1.5, P = .005), verbal memory (paired associate learning and Peterson paradigm; d = 4.3 and 1.6, P < .001), and an incidental learning task (d = 2.3; P = .001). Frequent subjective complaints as assessed by questionnaire were attenuated motivation (d = 1.7; P = .001), increased fatigue (d = 1.6; P = .001), distractibility (d = 1.0; P = .003), and depressed mood (d = 1.9; P = .004). PCP blood level was significantly associated with paired-associate learning, Benton Test, and reading/naming speed.

CONCLUSIONS

Long-term low-dose exposure to WPC in the domestic environment could be related to subjective complaints (attention, mood, and motivation) and to subtle alterations of neurobehavioral performance (e.g., working memory) in women.

Pentachlorophenol exposure in women with gynecological and endocrine dysfunction

Exposure to wood preservatives containing pentachlorophenol (PCP) was detected in 65 women who consulted the Endocrinological Department of the University Hospital of Obstetrics and Gynecology, Heidelberg, Germany, because of gynecological problems. Blood PCP levels ranged from 20.7 to 133 microg per liter of serum. One hundred and six women with similar clinical conditions, corresponding age and body weight, no PCP exposure in history, and PCP levels below 20 microg per liter of serum served as control group. Significant associations were found between serum PCP concentrations, age, and different parameters of the endocrine system. PCP may act centrally on a hypothalamic or suprahypothalamic level which may result in mild ovarian and adrenal insufficiency. PCP may, therefore, play a role in the increasing infertility problem.

Endocrine and reproductive function in ewes exposed to the organochlorine pesticides lindane or pentachlorophenol

The effects of lindane (LIN, gamma-hexachlorocyclohexane) and pentachlorophenol (PCP) on reproduction and general endocrine function were examined in breeding ewes as a model for wild and domestic ungulates, which may be exposed to low levels of pesticides that are potential endocrine-disrupting chemicals. Ewes (n = 13/group) were fed either a control untreated diet (CON), or a diet treated with LIN (1 mg/kg/d) or PCP (1 mg/kg/d) during the 5 wk prior to mating and throughout pregnancy and lactation. Mating response, ovulation rate, follicle and corpus luteum size, gestation length, pregnancy rate, lambing rate, and lamb birth weight were recorded. After weaning, 6 ewes from each group were bled at 15-min intervals for 8 h during the day and night and for 1 h before and 5 h after i.v. administration of gonadotropin-releasing hormone, thyroid-stimulating hormone (TSH), and adrenocorticotropin, to measure serum concentrations of luteinizing hormone, follicle-stimulating hormone, thyroxine (T4), and cortisol. Ewes were then killed and endocrine tissues examined histologically. Pregnancy rate as a result of matings taking place at the synchronized estrus was significantly decreased by the lindane treatment However, PCP and lindane did not markedly affect any other aspect of reproductive function studied. In PCP-treated ewes, serum concentrations of T4 were significantly reduced compared to control ewes during the day and night; however, the T4 response to TSH was not altered by PCP treatment. No other measured endocrine parameters were consistently affected by lindane or PCP. Thyroid follicle size was significantly increased in the LIN and PCP ewes compared to the control ewes. Low serum concentrations of T4 in the PCP ewes may have resulted in increased TSH secretion and increased thyroid follicle size. In conclusion, although pesticide treatments had no serious adverse effects on reproductive function in breeding ewes, PCP reduced T4 concentration, which in the long term could influence reproductive and general performance.

Chlorinated hydrocarbons in women with repeated miscarriages

This study was conducted to investigate a possible etiological role of chlorinated hydrocarbons in the pathogenesis of repeated miscarriages. The blood levels of chlorinated hydrocarbons [CHCs: pentachlorophenol, hexachlorocyclohexane, hexachlorobenzene, the dichlorodiphenyltrichloroethane (DDT) group, polychlorinated biphenyls] were determined in 89 women with repeated miscarriages, who were referred to the University Hospital of Obstetrics and Gynecology of Heidelberg for investigations between 1989 and 1993, and compared to a previously investigated reference population. In more than 20% of the women, at least one of the CHC levels exceeded the reference range. CHC levels did not differ significantly between women with primary or secondary and early or late miscarriages; neither did they differ between women with hormonal or immunological disorders as causes of repeated miscarriages or women with idiopathic repeated miscarriages. No significant associations were detected between CHC levels and further conceptions or the outcome of further pregnancies. As significant associations were found between increasing CHC blood concentrations and immunological and hormonal changes, CHCs may have an impact on the pregnancy course in certain cases.

Sensitive spectrophotometric method for determining pentachlorophenol in various environmental samples

A new, simple, and sensitive spectrophotometric method is described for determination of pentachlorophenol, a widely used insecticide and herbicide, in various environmental samples. The method is based on the reaction of pentachlorophenol with concentrated nitric acid to form chloranil, which liberates iodine from potassium iodide. The liberated iodine then selectively oxidizes leucocrystal violet to form crystal violet, which has an absorption maximum at 592 nm. Beer's law is obeyed over the concentration range of 0.1-1.6 micrograms pentachlorophenol/25 mL (0.004-0.064 ppm). The method was applied satisfactorily to determination of pentachlorophenol in air, water, plant material, textile effluent, and biological samples.

Effects of drinking pattern on the peak/trough blood concentrations in drinking water studies

The effects of changes in drinking patterns on the expected peak/trough blood concentrations of test compounds were examined during rodent dosed drinking water studies. They were based on the assumption that the kinetics of the test compound is linear and time-invariant. Results indicate that drinking patterns have minor effects on the expected peak/trough concentrations and the time to reach these concentrations. If a 12-hr light/dark cycle starting at 7.00 is used for all the drinking patterns studied, the peak and trough concentrations will occur in the early morning and late afternoon, respectively. A comparison of the predicted versus experimentally determined pentachlorophenol (PCP) plasma concentrations in a 1-wk rat drinking water study revealed that using a circadian rhythm drinking pattern in the model generated the most satisfactory prediction. Predictions based on a square wave drinking pattern with 90% drinking activities in the night phase were also excellent. Triangular or sinusoidal drinking patterns were least accurate in predictions.

Impaired in-vitro lymphocyte responses in patients with elevated pentachlorophenol (PCP) blood levels

Immune parameters were examined in 188 patients who were exposed for more than 6 mo to pentachlorophenol-containing pesticides. Blood levels of pentachlorophenol, lymphocyte subpopulations, in-vitro responses to mitogenic and allogeneic stimulation, plasma neopterin levels, and plasma cytokine and cytokine receptor levels were determined. Impaired in-vitro lymphocyte stimulation responses were impaired in 65% of the patients. The likelihood of impaired lymphocyte stimulation increased significantly with levels of pentachlorophenol that exceeded 10 microliters/l (p < .05). Patients who had high blood levels of pentachlorophenol and abnormal lymphocyte stimulation also had increased proportions of blood monocytes in blood (p < .05), as well as increased IL-8 serum levels (p < .02). Eleven patients who had abnormal mitogen stimulation experienced decreased CD4/CD8 ratios of < 1.0; 5 of these patients had decreased CD4+ lymphocyte counts of < 500/microliters, and 3 patients had increased plasma neopterin of > 15 nmol/l. These results indicate that increased levels of pentachlorophenol in blood can lead to severe T lymphocyte dysfunction.

Hexachlorobenzene-induced hypothyroidism. Involvement of different mechanisms by parent compound and metabolite

Rats received repeated oral treatment with different doses of hexachlorobenzene (HCB) (0-3.5 mmol/kg) for 2 or 4 weeks. Measurements of thyroid hormone status after 2 weeks showed a dose-dependent decrease of total thyroxine (TT4) levels, decreased free thyroxine (FT4) levels and little change of total triiodothyronine (TT3) levels. The effects on thyroid hormone status were more pronounced after 4 weeks and also included increased thyroid stimulating hormone (TSH) levels. These conditions suggest that HCB had induced hypothyroidism in these animals. Indications for occupation of thyroid hormone binding proteins were found in serum of exposed animals. The major metabolite pentachlorophenol (PCP) also caused, by competitive interactions with thyroid hormone binding proteins in serum, a rapid and dose-dependent decrease of TT4 and FT4 levels, but not of TT3 levels in serum. The decrease of serum TT4 levels by repeated dosing with 3.5 mmol HCB/kg for 4 weeks could be attributed to competitive interactions of PCP with hormone serum binding proteins and to increased metabolism induced by HCB to an equal degree. At lower dose levels or with shorter dosing periods, increased metabolism of T4 is the main cause of decreased TT4 serum levels. This is the first indication that a similar effect is caused simultaneously by the parent compound and its metabolite through different and independent mechanisms.

Pentachlorophenol carcinogenicity: extrapolation of risk from mice to humans

1. Pentachlorophenol (PCP) has been found to be carcinogenic in mice. The objective of this study was to extrapolate to humans the risk of cancer from data obtained in mice using information on disposition, serum protein binding and metabolism of PCP across species. 2. A review of the literature indicates that neither PCP nor a mutagenic metabolite, tetrachlorohydroquinone (TCHQ), has been specifically identified as responsible for the carcinogenicity. In addition, the occurrence of TCHQ as a metabolite of PCP in humans is still questionable. Therefore, cancer risk assessment is performed on the assumption that PCP itself is responsible for the carcinogenicity. 3. For interspecies extrapolation, a new method in which interspecies differences in clearance and serum protein binding are taken into account is used. The method gives estimates of equivalent human doses of PCP which are up to 4 times smaller than those obtained using body surface area. For both interspecies extrapolation methods, the estimated virtually-safe doses of PCP are smaller than the average daily intakes reported in groups of subjects nonspecifically exposed to PCP. Corresponding extra risks of cancer for lifetime exposure are from 20 to 140 times greater than the acceptable extra risk (10(-6)). The results obtained with this approach indicate that PCP is a possible public health hazard.

Toxicokinetics of pentachloroanisole in F344 rats and B6C3F1 mice

1. Toxicokinetics of pentachloroanisole (PCA) were studied in F344 rat and B6C3F1 mouse of both sexes by gavage at doses of 10, 20 and 40 mg/kg and by i.v. at 10 mg/kg. 2. PCA was rapidly demethylated to pentachlorophenol (PCP) in both rat and mouse and the resulting PCP plasma concentrations were much higher than that of parent PCA due to the much smaller apparent volume of distribution of PCP. 3. Peak plasma concentrations of PCA and PCP increased with dose in both rat and mouse. 4. Bioavailability of PCA was low in both rat and mouse and was sex independent. 5. The high plasma concentrations and relatively long biological half-life of PCP in both species after both i.v. and oral dosing with PCA indicate possible bioaccumulation of PCP upon multiple oral administrations of PCA.

Modeling blood/plasma concentrations in dosed feed and dosed drinking water toxicology studies

A computer model for predicting blood/plasma concentrations of test chemicals in dosed feed and dosed drinking water toxicology studies was developed. The model was constructed based on linear theory. The animal's feeding and drinking habits and the linear disposition kinetics of the test chemical obtained after a bolus gavage dose were built into the model. Blood/plasma concentrations of oxazepam and pentachlorophenol in dosed feed and dosed drinking water studies were predicted and compared with the experimentally determined data. The model proved highly reliable in predicting the blood/plasma concentrations of test chemical in dosed feed and dosed drinking water studies. The results suggest that if the kinetics of test chemicals fit a one-compartment model then bioaccumulation of the test chemical will occur in dosed feed or in dosed drinking water studies when absorption half-lives are less than 1.38 hr and elimination half-lives are longer than 5 hr. The extent of accumulation is mainly dependent on the elimination half-lives. For chemicals with absorption half-lives less than 1.38 hr and elimination half-lives less than 2 hr, the extent of bioaccumulation will be minimal. Blood/plasma concentrations of test chemicals in rats and mice will fluctuate daily and a quasi-steady state will be achieved after ad libitum exposure to dosed feed or dosed drinking water for approximately 4 days. If a daily 12-hr light cycle is used with the light cycle starting at 7:00 AM, the expected peak and trough blood concentrations in dosed feed studies will occur approximately in the early morning (5:00 AM) and in the late afternoon (4:00 PM), respectively. Similar results were obtained for dosed drinking water studies. The model should be applicable to dosed feed and dosed drinking water studies using other species.

Pharmacokinetic concepts in assessing intake of pentachlorophenol by rats after exposure through drinking water

The objective of this study was to predict concentrations of a toxicant in plasma after exposure to the toxicant through drinking water using basic pharmacokinetic principles. As an example, we studied pentachlorophenol (PCP), a widely used wood preservative of public health concern as an environmental pollutant. We added PCP to the drinking water (30 micrograms/mL) of five rats for 3 days. Blood was sampled, and water consumption was monitored every 12 h on the days 1 and 2 and every 3 h on day 3. After a 4-day washout, a PCP dose of 2.5 mg/kg was given intravenously, and blood was withdrawn at selected times for 2 days. PCP concentrations in plasma were measured by capillary gas chromatography. A one-compartment model with zero-order input and kinetic parameters (clearance, volume of distribution, and bioavailability) estimated after intravenous administration adequately predicted PCP concentrations in plasma during exposure to PCP. The average steady-state concentration (Css), which reflects the overall exposure, was predicted using the clearance (CL) concept [i.e., Css = (bioavailability.rate of intake)/CL] and compared with the observed value. The data for PCP demonstrate the potential utility of CL and other kinetic concepts in assessing exposure to a toxicant in drinking water, food, or air.

[Is it appropriate to consider wood preservative poisoning in the differential diagnosis of chronic recurrent respiratory tract infections?]

Wood preservatives as pentachlorophenol and lindane containing the highly toxic compound dioxin were common to be used to protect woods inside the house. In a case report a couple of symptoms are shown as upper airway irritation with dry mucosa, headaches, sleeplessness, lack of concentration and psychosomatic problems caused by those wood preservatives. The typical sequence of the symptoms is given. The results of blood and urine analysis on pentachlorophenol and lindane lead to investigations on indoor materials, air and dust. Taking out the contaminated materials is the best and only treatment.

Simultaneous assay of pentachlorophenol and its metabolite, tetrachlorohydroquinone, by gas chromatography without derivatization

A sensitive capillary gas chromatographic method was developed for the simultaneous determination of pentachlorophenol and its major metabolite, tetrachlorohydroquinone, in plasma, urine and feces. The method involved a simple one-step liquid-liquid extraction with diethyl ether and electron-capture detection gas chromatography on a fused-silica capillary column coated with 50% methylsilicone-50% trifluoropropylsilicone. The detection limit of both compounds was 50 ng/ml in plasma (from an initial volume of 0.1 ml), 100 ng/ml in urine and 100 ng/g in feces. Optimal conditions for both chemical and enzymatic hydrolysis were defined to measure conjugates of both pentachlorophenol and tetrachlorohydroquinone in urine. Tetrachlorohydroquinone was found to be unstable in plasma and urine; means to prevent its degradation during sample collection and storage by addition of ascorbic acid and ethylenediaminetetracetic acid are presented. This chromatographic method was shown to be precise, accurate and specific. It was successfully applied to toxicokinetic studies in rat.

Liquid chromatographic determination of pentachlorophenol in serum, using pre-column phase-transfer catalysed dansylation and post-column photolysis with fluorescence detection

Dansylation of pentachlorophenol was carried out after solid-phase extraction of acidified human serum and desorption with dichloromethane, in a dichloromethane-water two-phase system using tetrabutyl-ammonium bromide as the phase-transfer catalyst. Derivatisation was complete within 2 min at room temperature. After evaporation of an aliquot of the organic phase, the residue was dissolved in methanol and injected into a reversed-phase chromatographic system, equipped with a post-column photochemical reactor. In the reactor, dansylated pentachlorophenol is converted into highly fluorescent products. The recovery of the analyte from serum was 85 +/- 4%. Calibration graphs for horse and human serum were linear over two decades, with correlation coefficients ranging from 0.996 to 0.999. The detection limit of pentachlorophenol in horse and human serum was 400 pg ml-1. The reproducibility of the total procedure for a human serum sample containing 4 ng ml-1 was 4.5%.

Plasma binding of 1-butanol, phenol, nitrobenzene and pentachlorophenol in the rainbow trout and rat: a comparative study

1. The in vitro binding of 1-butanol, phenol, nitrobenzene, and pentachlorophenol in trout plasma and rat plasma was determined. 2. Binding to rainbow trout plasma proteins agreed within 9% of that observed in rat plasma. 3. Percentage bound to rainbow trout (2-99%) or rat (10-99%) plasma proteins increased as the log octanol/water partition coefficient of the chemicals increased within the Log P 1-3 range, and was suggestive of hydrophobic interactions in binding.

Pentachlorophenol and hexachlorobenzene in serum and urine of the population of Barcelona

1 Urinary chlorophenols of the general population of Barcelona, Spain were determined. Pentachlorophenol (PCP: 25.0 +/- 3.9 ng/ml; mean +/- s.e.m., n = 50) and tetrachlorophenol (TCP: 6.2 +/- 1.6 ng/ml; mean +/- s.e.m., n = 25) were found in all samples. 2 Pentachlorophenol and hexachlorobenzene were also determined in serum. Both were present in all samples (PCP: 21.9 +/- 1.9 ng/ml; HCB: 11.1 +/- 1.1 ng/ml; mean +/- s.e.m., n = 100). Their concentrations do not show any correlation, suggesting no metabolic relation between them.

Sister chromatid exchange and chromosomal breakage in pentachlorophenol (PCP) exposed workers

A cytogenetic study was performed on 20 healthy workers exposed to pentachlorophenol (PCP) in concentrations ranging from 1.2 to 180 micrograms/m3 (Maximum Concentration at the workplace is 500 micrograms/m3) for 3 to 34 years. PCP was determined in the blood plasma of all probands, yielding concentrations between 23 and 775 micrograms/l (Biological Tolerance Value is 1000 micrograms/l). In vitro PCP up to 90 mg/l was added to phytohaemagglutinin stimulated lymphocytes of normal healthy donors without any effect on sister chromatid exchange (SCE) or chromosomal aberrations (CA), whereas a slowdown of cell proliferation could be detected in the presence of 60 mg PCP/l. In vivo we neither observed a relation between PCP concentrations and the number of SCE nor an increase of CA.

Thermotropic properties of human erythrocyte membrane proteins as affected by hydroxychloroaromatic compounds

The thermal stability of the anion transport protein (band 3) and other proteins of the human erythrocyte membrane, as influenced by hydroxychloroaromatic (HO-Cl2-Ar) compounds, was studied by differential scanning calorimetry. Various hydroxychlorodiphenyl ethers (HO-Clx-DPEs) and hexachlorophene, but not pentachlorophenol, caused a marked decrease in the thermal stability of band 3. Most of the other calorimetric transitions of the erythrocyte membrane were only slightly affected. The activity of HO-Clx-DPEs toward lowering the transition temperature of band 3 generally increased with the degree of chlorination, and was somewhat dependent on the position of hydroxyl substitution. At higher concentrations of HO-Clx-DPEs, there was a decrease in the enthalpy change and a broadening of the endothermic transition of band 3. The order of effectiveness of these compounds, as determined from band 3 denaturation temperatures, was similar to the order of potency previously observed for hemolysis of human erythrocytes.

[Pentachlorophenol concentrations in the organs and blood of 11 dead infants]

For 11 children, died on age between 2.5 and 57 month due to different causes, the concentrations of pentachlorophenol in liver, kidney, brain and blood were located in the lower part of the spread of test values found for adults which had died in the same region and during the same time phase. The concentrations of pentachlorophenol in the blood of the 11 children were compared further with the findings from 20 living children with an age up to 10 years and were all located below the median of the test values (45,4 micrograms PCP/1) from the group last mentioned. There are no hints for connections between the body-burden of pentachlorophenol and the death-cases concerning the 11 children.

Absorption study of pentachlorophenol in persons working with wood preservatives

Plasma and urinary pentachlorophenol (PCP) was measured in 209 workers who had occupational exposure to wood preservatives containing this compound and 101 workers not exposed occupationally to PCP. Workers were examined for chloracne and blood concentrations of bilirubin, gamma-glutamyltransferase (GGT), cholesterol and high-density lipoproteins (HDL) were determined. All the occupationally exposed groups showed evidence of PCP absorption; highest mean concentrations were found in remedial timber-treatment operatives (6.0 mmol/l for plasma and 274 nmol/mmol of creatinine for urine). Timber-yard workers also showed substantial evidence of absorption (mean plasma concentration 4.8 mmol/l). Persons formulating PCP-containing wood preservatives had the lowest concentrations of any exposed group sampled (mean plasma concentration 1.3 mmol/l, mean urinary concentration 39.6 nmol/mmol of creatinine). The occupational groups studied were not standardized for factors known to affect bilirubin, GGT, cholesterol and HDL. The inference that can be drawn from the results of these measurements is therefore limited. There was, however, no evidence of any disadvantageous effect of PCP on health as measured by these parameters. No overt case of chloracne was found.

Pharmacokinetics of pentachlorophenol in man

Pentachlorophenol (PCP) was given orally to three volunteers at single doses of 3.9, 4.5, 9, and 18.8 mg. Daily urinary excretion of PCP and PCP conjugated to glucuronic acid was monitored using gas chromatography with electron capture detection (GC/ECD). Based on first-order elimination kinetics an elimination half-life of 20 days was derived. To eliminate interference by the uncontrolled absorption of PCP from the environment 0.98 mg 13C-PCP was taken by one of the volunteers. PCP levels in urine and plasma were determined using mass spectrometry (GC/MS) with negative chemical ionization. An elimination half-life of 17 days was found in both urine and blood. The collected data were used to calculate the clearance of PCP: a value of 0.07 ml/min was found. The long elimination half-life of PCP is explained by the low urinary clearance due to the high plasma protein binding (greater than 96%) and the tubular reabsorption. The pH-dependency of the elimination of PCP was investigated, and a distinct increase in the daily excretion was observed following alkalinization by oral administration of sodium bicarbonate. In order to elucidate the role of the enterohepatic circulation as a possible pool for PCP in humans, the bile of cholelithiasis patients with postoperative T-drainage was investigated for PCP and compared with the corresponding urine and plasma levels, but no accumulation of PCP in the enterohepatic circulation could be observed. The daily elimination and plasma levels of PCP in a group of individuals without a specific exposition were found to range from 10 to 48 micrograms/day and 19 to 36 micrograms/1, respectively.

Plasma pentachlorophenol concentrations in calves exposed to treated wood in the environment

Six calves were fed grain and hay from a pentachlorophenol (PCP)-treated feeder twice daily. Samples of blood were collected twice a week. Plasma PCP concentrations increased rapidly to a maximum of 1,086 microgram/L within 10 days. After the 3rd week, calves were denied access to the treated feeder; PCP values returned rapidly to near base line (before calves were fed from the treated feeder). After base-line plasma PCP values were reached, 4 of the 6 calves were housed in a total confinement building and exposed (by inhalation) to lumber that was commercially treated with PCP. The building itself was free of structural PCP-treated lumber. The ratio of building volume to treated wood surface was approximately 49 to 1. During the 3 weeks the calves were confined, PCP values did not increase and were markedly lower than those associated with oral exposure to treated wood. Oral dosing of calves with PCP in capsules--0.05 and 0.5 mg/kg--resulted in maximal plasma PCP values of 1,449 and 9,555 micrograms/L, respectively. Oral exposures (feeding from contaminated feeder; capsule) appeared to be more important than inhalation in causing increased plasma PCP concentrations in cattle. Exposure from these sources may be estimated by comparison with experimental values from dose-response studies. Feeding from treated feeders resulted in lower plasma PCP values than did dosing with 0.05 mg/kg daily.

Use of pentachlorophenol as long-term inhibitor of sulfation of phenols and hydroxamic acids in the rat in vivo

Inhibition of sulfation of the phenolic compound harmol (7-hydroxy-1-methyl-9H-pyrido[3,4-b]indole) by pentachlorophenol (PCP) was studied in the Wistar rat: PCP was administered in various ways to find a convenient method for long-term inhibition of sulfation. High doses of PCP or sodium pentachlorophenolate (NaPCP) in the diet (350 ppm) or NaPCP in the drinking water (1.4 mM) of Wistar rats for one week inhibited the sulfation of harmol by 30-45%. The plasma concentration of PCP in rats with NaPCP (1.4 mM) in their drinking water was highest (270 microM) in the period that the animals were kept in the dark and consumed food and water. This is explained by a rapid elimination: the elimination of PCP from plasma, after intravenous administration, showed a biphasic disappearance curve with half-lives of 2.17 and 7.24 hrs, respectively. This is much faster than in Sprague-Dawley rats. A log-linear correlation was found between the plasma concentration of pentachlorophenol and the inhibition of harmol sulfation. Although administration of NaPCP to rats in their drinking water inhibited the sulfation of harmol only by 45%, it inhibited the sulfation of the carcinogenic arylhydroxamic acid N-hydroxy-2-acetylaminofluorene by 70-75%.