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

Combined effects of pentachlorophenol and nano-TiO2 with different sizes on antioxidant, digestive, and immune responses of the swimming crab Portunus trituberculatus

Marine nano-titanium dioxide (nano-TiO2) and pentachlorophenol (PCP) pollution are escalating concerns in coastal areas. This study investigated the combined effects of continuous exposure to nano-TiO2 (25 nm, 100 nm) and PCP (0, 1, 10 μg/L) for 28 days on the antioxidant, digestive, and immune abilities of the swimming crab Portunus trituberculatus. Compared with the control group, the interaction between nano-TiO2 and PCP was significantly higher than exposure to a single stressor, with a pronounced decrease in amylase activity observed due to the reducing nano-TiO2 particle sizes. Resulting in increased MDA and SOD activity. The expression levels of Toll4, CSP3, and SER genes in crab hemolymph showed perturbations following exposure to nano-TiO2 and PCP. In summary, according to the results of CAT, GPX, PES and AMS enzyme activities, it was concluded that compared to the larger particle size (100 nm), the single stress of nano-TiO2 at a smaller particle size (25 nm) and co-stress with PCP have more significant impacts on P. trituberculatus. However, the potential physiological regulation mechanism of the interaction between these pollutants remains elusive and requires further study.

Pain Pathways: Linking Environmental Pollutants with Migraine-Associated Pain Signaling

Using human cells and a mouse study, researchers found that pesticides, phthalates, hormone-like compounds, and other chemicals affected the TRPA1 channel-which is also implicated in migraine.

Xenobiotic Exposure and Migraine-Associated Signaling: A Multimethod Experimental Study Exploring Cellular Assays in Combination with Ex Vivo and In Vivo Mouse Models

BACKGROUND

Mechanisms for how environmental chemicals might influence pain has received little attention. Epidemiological studies suggest that environmental factors such as pollutants might play a role in migraine prevalence. Potential targets for pollutants are the transient receptor potential (TRP) channels ankyrin 1 (TRPA1) and vanilloid 1 (TRPV1), which on activation release pain-inducing neuropeptide calcitonin gene-related peptide (CGRP).

OBJECTIVE

In this study, we aimed to examine the hypothesis that environmental pollutants via TRP channel signaling and subsequent CGRP release trigger migraine signaling and pain.

METHODS

A calcium imaging-based screen of environmental chemicals was used to investigate activation of migraine pain-associated TRP channels TRPA1 and TRPV1. Based on this screen, whole-cell patch clamp and in silico docking were performed for the pesticide pentachlorophenol (PCP) as proof of concept. Subsequently, PCP-mediated release of CGRP and vasodilatory responses of cerebral arteries were investigated. Finally, we tested whether PCP could induce a TRPA1-dependent induction of cutaneous hypersensitivity in vivo in mice as a model of migraine-like pain.

RESULTS

A total of 16 out of the 52 screened environmental chemicals activated TRPA1 at 10 or 100 μ M . None of the investigated compounds activated TRPV1. Using PCP as a model of chemical interaction with TRPA1, in silico molecular modeling suggested that PCP is stabilized in a lipid-binding pocket of TRPA1 in comparison with TRPV1. In vitro, ex vivo, and in vivo experiments showed that PCP induced calcium influx in neurons and resulted in a TRPA1-dependent CGRP release from the brainstem and dilation of cerebral arteries. In a mouse model of migraine-like pain, PCP induced a TRPA1-dependent increased pain response (N total = 144 ).

DISCUSSION

Here we show that multiple environmental pollutants interact with the TRPA1-CGRP migraine pain pathway. The data provide valuable insights into how environmental chemicals can interact with neurobiology and provide a potential mechanism for putative increases in migraine prevalence over the last decades. https://doi.org/10.1289/EHP12413.

pH-dependent ecological risk assessment of pentachlorophenol in Taihu Lake and Liaohe River

Pentachlorophenol (PCP) has been reported toxic to aquatic organisms, and it frequently occurs at relatively high concentrations in most Chinese waters due to the re-emergence of schistosomiasis since 2003. Several studies about Water Quality Criteria (WQC) for PCP had been performed to protect the aquatic ecosystem, but in most of these studies the toxicity data were not properly analyzed (e.g. screening and processing methods). Moreover, little study was carried out on the ecological risk assessment (ERA) based on environmental factors. In this study, through collecting published native toxicity data of PCP along with relationships between toxicity and pH, pH-dependent WQC was established using a standardized scientific statistical method in China. The Criterion Maximum Concentration (CMC) and Criterion Continuous Concentration (CCC) were expressed as a function of pH. These were (1) CMC = exp(1.361×pH-8.034) and (2) CCC = exp(1.361×pH-10.434). At pH 7.8, the derived CMC and CCC were 13.21 and 1.20μg/L, respectively. In addition, four tiers of the ERA were conducted based on pH for different waterbodies at different seasons. In tiered 1, 2, 3 and 4 ERA, PCP exposure concentrations were standardized to that at pH 7.8. Results showed that all levels of ERA method in the tiered framework were consistent with each other, and the risks of PCP in Liaohe river of wet season, Taihu lake and Liaohe river of dry season increased successively. The Hazard quotient (HQ) method indicated that small fluctuations in pH would lead to misleading hazard results. PCP concentrations of 8.66μg/L at pH 7.37 in one site posed more risk than PCP of 9.57μg/L at pH 7.93 in another site. The joint probability suggested that ecological risks may exist 11.84% in the dry season and 1.51% in the wet season in Liaohe River, and 4.98% in Taihu Lake, respectively while 5% thresholds (HC₅) were set up to protect aquatic organisms. We hope this work could provide more information to manage and control PCP pollution in Taihe Lake and Liaohe River.

Transcriptional changes induced by in vivo exposure to pentachlorophenol (PCP) in Chironomus riparius (Diptera) aquatic larvae

Pentachlorophenol (PCP) has been extensively used worldwide as a pesticide and biocide and is frequently detected in the aquatic environment. In the present work, the toxicity of PCP was investigated in Chironomus riparius aquatic larvae. The effects following short- and long-term exposures were evaluated at the molecular level by analyzing changes in the transcriptional profile of different endocrine genes, as well as in genes involved in the stress response and detoxification. Interestingly, although no differences were found after 12- and 24-h treatments, at 96-h exposures PCP was able to induce significant increases in transcripts from the ecdysone receptor gene (EcR), the early ecdysone-inducible E74 gene, the estrogen-related receptor gene (ERR), the Hsp70 gene and the CYP4G gene. In contrast, the Hsp27 gene appeared to be downregulated, while the ultraspiracle gene (usp) (insect ortholog of the retinoid X receptor) was not altered in any of the conditions assayed. Moreover, Glutathione-S-Transferase (GST) activity was not affected. The results obtained show the ability of PCP to modulate transcription of different biomarker genes from important cellular metabolic activities, which could be useful in genomic approaches to monitoring. In particular, the significant upregulation of hormonal genes represents the first evidence at the genomic level of the potential endocrine disruptive effects of PCP on aquatic invertebrates.

Systematic review of pentachlorophenol occurrence in the environment and in humans in China: not a negligible health risk due to the re-emergence of schistosomiasis

Pentachlorophenol (PCP) has been widely used for killing snails in areas of China where schistosomiasis is epidemic. With the re-emergence of schistosomiasis, the warranted production and consumption of PCP has inevitably resulted in persistent environmental contamination by it and its impurities, polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). This study aimed to evaluate the contamination status and human burden of PCP and its impurities (PCDD/Fs) in China, considering the previous epidemic and re-emergence of schistosomiasis. We searched studies relevant to PCP occurrence in the environment and in humans in China. Data on snail elimination areas were included to estimate PCP consumption. Relevant publications were analyzed to distinguish PCDD/Fs contamination from PCP usage. PCP contamination was detected ubiquitously in various environmental media and in human samples; environmental levels were generally low, with the exception of some hot spots. In schistosomiasis-epidemic areas, there were significantly higher PCP levels in the environment and in humans than in control areas. Spatial disparities indicated the consistency between serious schistosomiasis epidemic areas and hot spots of PCP contamination. The data suggest an increased trend in PCP contamination of the environment. Specific PCDD/Fs contamination from PCP usage existed even at low environmental levels. The occurrence of PCP in the environment and in humans positively correlated with the epidemic of schistosomiasis. Thyroid-disrupting effects and cancer risk caused by PCP and PCDD/Fs even at low environmental levels in China's schistosomiasis-epidemic areas are of concern.

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.

Rapid evaluation of human biomonitoring data using pattern recognition systems

Assessing human biomonitoring data often necessitates dealing with fragmentary prior knowledge and a complex set of variables. A procedure for explorative data analysis via decision-tree analysis was undertaken to obtain high-level descriptive summary information on human exposure on a timely basis. This study is based on a subset of monitoring data of the Environmental Specimen Bank for Human Tissues within the German Environmental Specimen Bank (n sigma: 2401: 42/58% males/females; 34/66% born in East/West Germany). Three well-known xenobiotic organochlorines (XOCs) [sum of polychlorinated biphenyls (PCBs) 138 + 153 + 180, pentachlorophenol (PCP), and hexachlorobenzene (HCB)] were used as target variables. Meta-data regarding the samples and individuals were collected via a self-reported questionnaire and used as potential predictor variables. Prior to decision-tree analysis, XOC levels were adjusted (trend, lipids, creatinine, total protein) via stepwise linear regression. Adjusted XOC levels were subsequently utilized to identify relevant predictors of human XOC exposure using Exhaustive CHAID as a common decision-tree algorithm. Although overall tree model quality is generally poor, consistent and plausible predictors for human exposure were identified. Besides time trend and clinical parameters, the predominant predictors for HCB and PCB exposure were birthplace, gender, age, body mass index (BMI), and consumption of milk/dairy products or animal fats. For PCP, predominant predictors were sampling site, gender, and consumption of animal fats. Summing results of decision-tree models and regression models, explained variances for metric scaled XOC are: PCB (34.2%) > HCB (30.3%) > PCP (17.2%). Explorative analysis of human biomonitoring data based on simple decision-tree analysis provides valuable information for planning further investigations and statistical data for analyses to support prediction, consequences, and regulation of XOC.

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).

The Environmental Specimen Bank for Human Tissues as part of the German Environmental Specimen Bank

The German Environmental Specimen Bank for Human Tissues (ESBHum) as part of the German Environmental Specimen Bank (ESB) focuses on documenting and assessing trends of human exposure via real-time monitoring of body burden and long-term storage of samples under stable deep freezing conditions (-150 degrees C) for later retrospective analyses. Real-time monitoring is performed after completing sampling processes of one year and covers actually 20 inorganic and 5 organic substances. While concentrations of several substances, e.g., arsenic, cadmium and mercury, are remained unchanged over time, other substances, e.g., lead and pentachlorophenol (PCP), show a clearly perceptible decrease. Substances which are not routinely analyzed in real-time monitoring are retrospectively measured by indication in the stored human specimens. Indications of retrospective monitoring are availability of valid analytical methods, e.g., in case of PCDF and PCDD, or assessment of concentration trends of substances with actual interest of toxicology and/or environmental medicine, e.g., polybrominated diphenyl ethers (PBDE), perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). While over time the body burden of dioxins as well as PFOS and PFOA decreased, the PBDE concentrations in human blood increase. The observed decrease of blood lead and PCP levels over time is a consequence of legal prohibition and restriction. The time-dependent concentrations of the aforementioned substances agree with results of other national studies. So it can be concluded that the German ESBHum is an important instrument for health-related environmental observation and protection in Germany.

Persistent organochlorine pollutants in children working at a waste-disposal site and in young females with high fish consumption in Managua, Nicaragua

The aim of this study was to assess persistent organochlorine pollutant (POP) levels in serum collected from children (11-15 years old) working and sometimes also living at the municipal waste-disposal site in Managua, located at the shore of Lake Managua, and in nonworking children living both nearby and also far away from the waste-disposal site. The influence of fish consumption was further evaluated by assessing POPs levels in serum from young women (15-24 years old) with markedly different patterns of fish consumption from Lake Managua. 2,2-bis(4-chlorophenyl)-1,1,1-trichloro-ethane (4,4'-DDT) and 2,2-bis(4-chlorophenyl)-1,1-dichloro-ethene (4,4'-DDE), gamma-hexachlorocyclohexane (gamma-HCH), polychlorinated biphenyls, pentachlorophenol, and polychlorobiphenylols were quantified in all samples. In general, the levels observed were higher than those reported in children from developed countries, such as Germany and United States. Toxaphene, aldrin, dieldrin, and beta-HCH could not be identified in any sample. The children working at the waste-disposal site had higher levels of POPs compared with the nonworking reference groups. In children not working, there were also gradients for several POPs, according to vicinity to the waste-disposal site. Moreover, in children, as well as in young women, there were gradients according to fish consumption. The most abundant component was 4,4'-DDE, but at levels still lower than those reported in children from malarious areas with a history of recent or current application of 4,4'-DDT for vector control.

Pentachlorophenol inhibits micronuclei induction by 2-acetylaminofluorene but not by thioacetamide

Our study examined the capacity of pentachlorophenol (PCP) to inhibit the ability of 2-acetylaminofluorene (2-AAF) and thioacetamide (TAA) to induce micronuclei in mouse bone marrow cells in vivo. 2-AAF (5.6mg/kg) and TAA (60mg/kg) were administered intra-peritoneally (i.p.) to Mus musculus males (BALB/c), and the frequencies of polychromatic erythrocytes with micronuclei (PCE-MN) 24h after injection were analyzed. Treatment with 2-AAF or TAA resulted in high PCE-MN frequencies in comparison with untreated and negative controls (19.9 and 21.6‰, respectively, versus ≈3‰). Pretreatment with a single PCP dose (44mg/kg) 24h prior to the 2-AAF administration virtually eliminated micronuclei formation by 2-AAF, although it had no inhibitory effect on TAA-induced micronuclei. Animals receiving cyclophosphamide (CP) served as positive control. Since PCP is known to inhibit arylsulfotransferase (AST) activity, which is involved in 2-AAF activation, this mechanism most likely produced the results with PCP and 2-AAF. Our results also are consistent with a different pathway involved in TAA induction of micronuclei, one that is not inhibited by PCP.

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.

Analytical methods for biological monitoring of exposure to pesticides: a review

Synthetic pesticides have been used since in the early to mid twentieth century. In the US alone, over 800 pesticide active ingredients are formulated in about 21,000 different commercial products. Although many public health benefits have been realized by the use of pesticides, their potential impact on the environment and public health is substantial. For risk assessment studies, exposure assessment is an integral component, which has unfortunately, often been weak or missing. In the past several decades, researchers have proposed to fill these missing data gaps using biological monitoring of specific markers related to exposures. In this paper, we present a review of existing analytical methodology for the biological monitoring of exposure to pesticides. We also present a critical assessment of the existing methodology and explore areas in which more research is needed.

Development and evaluation of an immunoassay for biological monitoring chlorophenols in urine as potential indicators of occupational exposure

Trichlorophenols (TCP) eliminated by the urine can be considered as potential biomarkers of exposure of many chemicals (chlorophenols, chlorophenoxy acid herbicides, prochloraz, lindane, hexachlorobenzene, etc). High-throughput screening methods are necessary to carry out efficient monitoring programs that may help to prevent certain occupational health diseases. For this purpose, an indirect enzyme-linked immunosorbent assay (ELISA) for 2,4,6-trichlorophenol detection has been developed using polyclonal antisera raised against 3-(3-hydroxy-2,4,6-trichlorophenyl)propanoic acid (hapten 5) covalently coupled by the mixed anhydride (MA) method to keyhole limpet hemocyanin (KLH). The indirect ELISA uses a heterologous coating antigen prepared by conjugation of 3-(2-hydroxy-3,6-dichlorophenyl)propanoic acid (hapten 4) to bovine serum albumin (BSA) using the active ester (AE) method. The optimum hapten density for the coating antigen was found to be 3 mol of hapten/mol of protein. The assay shows a limit of detection of 0.245 +/- 0.116 microg L(-1), and it is performed on 96-well microtiter plates in about 1.5 h. The ELISA reported recognizes on a much less extent other chlorinated phenols, such as 2,3,4,6-tetrachlorophenol (2,3,4,6-TtCP, 21%), 2,4,5-TCP (12%) and 2,3,5-TCP (15%); however, brominated phenols (BP) are even more recognized than the corresponding chlorinated analogues (ex. 2,4,6-TBP, 710%; 2,4-DBP, 119%). With the aim of finding an explanation for this behavior, theoretical calculations have been performed for those and other halogenated phenols (2,4,6-triiodophenol and 2,4,6-trifluorophenol) to clarify which physicochemical parameter can explain better the recognition pattern observed. Finally, the assay has been adapted to the analysis of urine samples. The studies have shown that a limit of detection of 1 microg L(-1) can be accomplished on this biological matrix by combining the ELISA procedure with a C18 solid-phase extraction method.