PCBQ: Computerized quantification of total PCB and congeners in environmental samples

Computerized methodologies for the quantification of total PCBs, PCB in Aroclor mixtures and individual PCB congeners in environmental samples are presented. The method for total PCBs is based on a multiple-linear regression analysis using data from capillary gas chromatography of Arocolor standards. PCB congeners were identified and their weight percentages determined in Aroclor mixtures by GC/MS. PCB congeners and total PCBs were accurately quantified in predetermined test data and environmental samples.     

Congener profiles of PCB and a proposed new set of indicator congeners

In this study, a new method for calculating total PCB and toxic equivalents (TEQ) of coplanar PCB (Co-PCB) was proposed, called the 'PCB dual method'. This method analysed various kinds of technical PCB, samples contaminated by technical PCB and byproduct PCB. In the PCB dual method, a data set of 15 indicator congeners was utilized for the calculations, having IUPAC nos. #3, #8, #28, #52, #77, #101, #105, #118, #126, #138, #153, #180, #194, #206 and #209. The 15 congener set was chosen from the major congeners, determined by HRGC/HRMS analysis, in 18 technical PCB, Kanechlor, Aroclor, Clophen and Chlorofen, and 20 other samples, such as indoor air, flue gases, emission gases, municipal solid waste (MSW), ash and sealant. To obtain total PCB and TEQ of Co-PCB, the intermediate sum for the concentration of the 15 congeners was multiplied by each multiplication factor. As a result, we obtained the average factor used to calculate total PCB in technical PCB and other samples. For technical PCB, the factor was 3.01, while for indoor air samples, flue and emission gases, MSW, ash and sealants, the factors were 3.92, 4.16, 3.68, 4.52 and 4.77, respectively. Moreover, the factor used to calculate the TEQ of Co-PCB in Kanechlor and other source samples were also obtained. The factors for Kanechlor, indoor air samples and emission gases from a cement plant were in the order of 10(-5), while the factor for flue gases in a MSW incinerator was in the order of 10(-3). These data were valuable for the rough estimation of the TEQ of Co-PCB without separation from other PCB before individual measurements.     

Comparison of an enzyme-linked immunosorbent assay (ELISA) to gas chromatography (GC)--measurement of polychlorinated biphenyls (PCBs) in selected US fish extracts

The analysis of PCBs in fish tissues by immunoassay methods was evaluated using fish collected from a US monitoring program, the National Contaminant Biomonitoring Program of the US Department of Interior, Fish and Wildlife Service. Selected composite whole fish samples, which represented widely varying concentrations and sources of PCBs, were extracted and subjected to congener PCB analysis by gas chromatography (GC) and total PCB analysis using an ELISA (ePCBs) calibrated against technical Aroclor 1248. PCB congener patterns in these fishes were different from the patterns found in commercial Aroclors or their combinations as demonstrated by principal component analysis of normalized GC congener data. The sum of the PCB congeners measured by GC (total-PCBs) ranged from 37 to 4600 ng/g (wet weight). Concentrations of PCBs as determined by the ELISA method were positively correlated with total-PCBs and the ePCBs/total-PCBs ratios for individual samples ranged from 1 to 6. Ratios of ePCBs/total-PCBs for dilutions of Aroclors 1242, 1254, and 1260 and for matrix spikes range from 0.6 for 1242 to 2.5 for 1254 and 1260. These results suggest that higher chlorinated PCB congeners have higher affinity for the anti-PCB antibodies. Partial least squares with latent variable analysis of GC and ELISA data of selected Aroclors and fish samples also support the conclusion that ELISA derived PCB concentrations are dependent on the degree of chlorination.     

Separation of non-ortho polychlorinated biphenyl congeners on pre-packed carbon tubes. Application to analysis in sewage sludge and soil samples

The analysis of planar (non-ortho) polychlorinated biphenyls (PCB) by HRGC-ECD or HRGC-HRMS requires a fractionation step to avoid the interferences of the bulk of PCB, usually in much higher concentration than the planar ones. In this paper, a new method, based on the fractionation of PCB on SPE commercial tubes pre-packed with Carbopack B, has been developed. After the extract has been applied on the stationary phase, the bulk of PCD are eluted with 15 ml of hexane (fraction I), mono-ortho PCB with 20 ml of hexane/toluene 99:1 (fraction II) and planar PCB with 20 ml of toluene (fraction III) in a station under vacuum. The method has been validated: accuracy (expressed as recovery in %) is >70% and precision (expressed as % RSD) is <20% considering changes of day, analyst and batch of tubes. The method is linear in the range studied. Other advantages are that the method is simple, rapid and it can be easily automated. The application of this separation to the determination of planar PCB in fly-ash extracts from an intercalibration exercise and to sewage sludge, sediment and soil samples has been successful. In addition, this method removes hydrocarbons from the planar PCB fraction and allows its concentration to very small volumes.     

Level, sources and toxicity of polychlorinated biphenyls in the Italian diet

We used the duplicate portion method to measure the daily dietary intake of total and congener-specific polychlorinated biphenyls (PCB) and to assess their potential toxicity in a group of 20 subjects consuming a typical Italian diet. The mean +/- SD intake of total PCB, measured by GC-MS, was 3.72 +/- 1.51 micrograms/person/day, comparable to values reported in similar studies world-wide, with individual intakes varying within one order of magnitude, from 0.97 to 10.59 micrograms/person/day. The di-ortho congeners 153, 18 and 138 were the PCB found in the highest concentrations (respectively 13.8%, 11.4% and 10.9% of the total) while the non-ortho coplanar congeners (77, 126 and 169) amounted to 0.5% of the total. The corresponding levels of toxicity (TCDD-like TEQ values ascribable to PCB) ranged from 4.6 up to 119 pg/person/day of TCDD-equivalents in 18 subjects, i.e. presumed no-risk levels, but with peaks of 2109 and 4553 pg/person/day in two subjects with significant intakes of the congener 126. Principal components analysis and redundancy analysis showed dairy products, meat and fish were the principal sources of PCB, and vegetables those with the highest toxicity index in the Italian diet.     

PCB congener distributions in muscle,liver and gonad of Fundulus heteroclitus from the lower Hudson River Estuary and Newark Bay

Gradients in sediment polychlorinated biphenyl (PCB) concentrations and PCB congener profiles exist along the Hudson River (NY, USA). We evaluated site and tissue differences in PCB concentration and congener profiles in resident mummichog (Fundulus heteroclitus) collected from PCB-contaminated sites in the lower Hudson River and the New York/New Jersey Harbor Estuary. Fish were collected from three PCB-contaminated sites Piermont Marsh (P), Iona Marsh (I), and Newark Bay (NB), and from two reference sites (Flax Pond, NY; Succotash Salt Marsh, RI). Congener profiles were statistically analyzed using principal component analysis (PCA) and general linear model (GLM) profile analysis. Contaminated fish had PCB tissue concentrations approximately 10-fold higher than those of reference fish. There were no site differences in PCB body burden (all tissues combined) among the contaminated site fish. However, relative PCB concentration did differ between organs: NB fish (gonad=liver>muscle); I and P fish (gonad>liver>muscle). In contrast to PCB content, PCB congener profiles did show site differences; NB mummichog being depleted in the less chlorinated congeners relative to I and P fish, likely reflecting different PCB sources to these populations. Within a site, however, PCB congener patterns were similar between liver, gonad and muscle. In conclusion, PCA and GLM analyses gave complementary results, both analyses indicating differences in site, but not tissue, distributions of PCB congeners. This study also demonstrates that unlike congener profiles, total PCB content does differ dramatically amongst tissues and further, that PCB differences among tissues (gonad vs. liver vs. muscle) can vary with site.     

A comparison of TEQ contributions from PCDDs,PCDFs and dioxin-like PCBs in sewage sludges from Catalonia,Spain

Eight sewage sludges from rural, urban and industrial wastewater treatment plants (WWTPs) in Catalonia (Spain) were analysed for polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs) to determine the present levels of contamination. A method based on an automated cleanup system followed by an isotope-dilution high-resolution mass spectrometric analysis was employed. Total toxicity equivalent (WHO-TEQ) values were calculated using the toxicity equivalent factors (WHO-TEFs) proposed by WHO for dioxin-like PCBs, PCDDs and PCDFs. The WHO-TEQ(PCDD/F) values for these samples ranged from 4.9 to 20.8 pg/g dry weight (d.w.), with a mean value of 9.3 pg/g d.w., whereas WHO-TEQ(PCB) levels ranged between 1.9 and 6.6 pg/g d.w., with a mean value of 4.2 pg/g d.w. The WHO-TEQ(PCB) contribution varied from 13% to 50%, suggesting that PCB contribution on the toxicity of the samples must be taken into account. Moreover, these contemporary PCDD, PCDF and PCB concentrations were compared with previous data obtained from sewage sludge samples collected during the 80s. Our findings show that contemporary PCDD, PCDF and PCB levels have declined since the 80s.     

Solid phase extraction with pyrenebutyric acid-bonded silica for analysis of polychlorinated biphenyls in sewage water by gas chromatography-mass spectrometry

A solid phase extraction (SPE) method using pyrenebutyric acid-bonded silica (PYB) as sorbent was developed to determine 23 polychlorinated biphenyls (PCBs) in sewage water by gas chromatography-mass spectrometry (GC-MS). Factors were optimized in SPE procedures including elution solvent, pH, and cartridge burden. The recoveries of 23 PCB congeners were 69.44-111.91% under optimized conditions. Comparisons were also conducted among PYB-SPE, C(18)-SPE and United States Environmental Protection Agency 608 (USEPA608) methods in the analysis of PCBs in sewage water samples. The results showed that the performance of PYB-SPE method was similar with USEPA608 method and better than C(18)-SPE method. Both PYB-SPE and USEPA608 methods were then employed to analyze PCBs in real spiked sewage water samples. The recoveries of PCB congeners determined by PYB-SPE method ranged from 70.6% to 92.4% in real spiked sewage water samples which were identified to be in accordance with USEPA608 method. Limits of detection (LOD) were in the range of 0.06-0.22ngL(-1) for PCB congeners. The optimized PYB-SPE method was successfully applied to the determination of PCBs in sewage water samples.     

Human biomonitoring of polychlorinated biphenyls and polychlorinated dibenzodioxins and dibenzofuranes in teachers working in a PCB-contaminated school

Eighteen teachers from a highly contaminated school and 11 teachers from a control school participated in this study. Total polychlorinated biphenyl (PCB) indoor air concentration (six indicator congeners x 5) was beyond 12000 ng/m3 in some rooms of the contaminated school. PCB 28 and PCB 52 were the prevailing congeners. Whole blood was taken from each participant by the local health authority, pooled in two groups and analysed for the six PCB indicator congeners, non-ortho PCBs and polychlorinated dibenzodioxins (PCDD)/polychlorinated dibenzofurans (PCDF). Blood analysis showed elevated mean PCB 28 and PCB 52 levels for the exposed group, however the two groups were almost identical with regard to PCB 101, 138, 153 and 180. Moreover no difference can be observed for the concentration of non-ortho PCBs and PCDD/PCDF. The data support the finding, that heavy indoor air contamination with low chlorinated PCBs causes an increase of PCB 28 and PCB 52 blood levels. However, this increment was small compared to their total PCB load.     

Detection of indoor PCB contamination by thermal desorption of dust. A rapid screening method?

Although PCB in caulking materials has been forbidden for many years in most of Europe, including Denmark, there has been continued interest to measure PCB levels in the air of contaminated buildings and blood of the occupants (Mengon and Schlatter 1993, Fromme et al. 1996, Ewers et al. 1998, Currado and Harrad 1998, Gabrio et al. 2000). The relatively low priority for investigations of this contamination is probably due to the small quantities inhaled compared to exposure via food, and the rapid metabolism of the most volatile congeners demonstrated by low concentrations of all congeners in the blood of exposed persons (Ewers et al. 1998, Gabrio et al. 2000). There is, however, evidence that PCB containing caulking materials have been used even during the '90s (Fromme et al. 1996). In Denmark, it is estimated that 75 t PCB is still in buildings (Organization of Sealant Branch's Manufacturers and Distributors 2000). During an investigation of dust from buildings with excessive microbial growth (including 35 rooms from 9 buildings), the analysis of semivolatile compounds by thermal desorption-GC/MS of samples from a single building surprisingly revealed large amounts of PCBs containing 3, 4 and 5 chlorine atoms, 10-20 times the amounts found in samples from other buildings. Extraction of the dust by SFE followed by GC/ECD analysis for 12 PCB congeners showed that there was approximately 20 times the total PCB concentrations in dust from the polluted building compared to the levels in the other buildings. Subsequent headspace analysis of caulking material from the polluted building revealed this to be the source. Shelf dust functions as a passive sampling medium and, thus, can be used as a screening method to detect PCB and other semivolatile pollution indoors.     

Detailed PCB congener patterns in incinerator flue gas and commercial PCB formulations (Kanechlor)

In this study, we determined the detailed PCB congener patterns in flue gases from eight incinerators and four commercial PCB formulations (Kanechlors). About 160 PCB peaks were identified in samples using a DB-5 column and HRGC/HRMS. The concentration of incinerator stack emission gas ranged from 0.02 to 44 ngWHO-TEQ/Nm3. The ratios of dioxin-like PCBs in the total PCB concentration were from 3.4% to 25.7% and from 0.63% to 9.1% in stack emission gases and Kanechlor samples, respectively. The PCB congener profiles of Kanechlor samples were similar to those of previous studies. To determine characteristic congeners in flue gas and Kanechlor samples, principal component analysis (PCA) of the data was conducted using STATISTICA for Windows 5.0J (StatSoft, Inc.). As a result, we obtained four principal components (PCs) and accounted for 74% of the total variance. PC 1 was interpreted combustion, PC 2 and PC 3 were interpreted the difference in the number of substituted chlorines and, PC 4 could not be determined. Moreover, we obtained three groups according to the PCB congeners pattern among samples by PCA. These specific congeners that represent characteristics of each class were identified. These data will be useful for the source analysis of PCBs in the environment.     

PCB and dioxin-like PCB in indoor air of public buildings contaminated with different PCB sources--deriving toxicity equivalent concentrations from standard PCB congeners

Data on dioxin-like PCB in indoor air of buildings with PCB-containing materials and on possible correlation between toxicity equivalent concentrations (TEQ) and levels of non-dioxin-like standard PCB is sparse. As part of a larger survey on indoor-air contamination with PCB, the connection between the concentration of standard PCB congeners and the dioxin-like toxicity expressed as TEQ was investigated. Indoor air samples (n=8) were collected in four public buildings with known PCB sources and total PCB levels in the range from 715 to 2250 ng/m3 and analyzed for the six non-dioxin-like standard PCB (congeners 28, 52, 101, 138, 153, 180), the twelve dioxin-like PCB congeners according to WHO and the 17 2,3,7,8-substituted PCDD/PCDF congeners. In three buildings where PCB were used as flame retardant coatings of acoustic ceiling tiles, PCB 101 had the maximum level among the six standard PCB, while in the building with permanent elastic sealants as PCB source, congeners 28 and 52 dominated the pattern by far. In the case of permanent elastic sealants as PCB source (n=3) a total PCB concentration of 1000 ng/m3 corresponded to a total TEQ level of 0.3-0.6 pg/m3. In contrast, in rooms with acoustic ceiling tiles as PCB source, 1.8-4.7 pg TEQ/m3 per 1000 ng total PCB/m3 were found. Linear regression analysis between PCB and TEQ indicated that PCB 118 might be used to calculate the total TEQ of dioxin-like PCB and PCDD/PCDF. By means of such a correlation it is possible to estimate TEQ by extrapolation from the results of less sophisticated analytical methods. It is tentatively recommended to use PCB 118 for screening purposes or re-evaluation of standard PCB indoor-air measurements. If only the six non-dioxin-like PCB standard congeners are available, a regression algorithm using the sum of PCB 101, 138, 153 and 180 might be used instead.     

Characterization and risk assessment of polychlorinated biphenyls in soils and vegetations near an electronic waste recycling site, South China

This study aimed at identifying the levels of PCBs generated from e-waste recycling, and their potential impacts on the soils and vegetations as well. The ΣPCBs concentrations in soil and plant samples ranged from 7.4 to 4000 ng g(-1) and from 6.7 to 1500 ng g(-1), respectively. For the plant samples, Chrysanthemum coronarium L. from vegetable field and the wild plant Bidens pilosa L. from the burning site showed relatively higher PCB concentrations than other species. For the soil samples, the e-waste burning site had relatively higher PCB concentrations than the adjacent areas, and vegetable soils had higher PCB concentrations than paddy soils. The PCB concentrations showed a clear decreasing trend with the increasing distance from the e-waste recycling site. PCB 28, 99, 101, 138, 153, and 180 were the predominant congeners. Principal component analysis results showed a potential fractionation of PCB compositions from the burning site to the surroundings. The PCB congener pattern at the burning site was similar to Arochlor 1260, pointing to an input of non-domestic e-waste. Similar PCB congeners were found in soils and related vegetables, indicating they derived from the same source. The consumption of vegetables grown in soils near e-waste recycling sites should be strictly avoided due to the high PCBs in the plant tissues.     

Development and validation of a method for analysis of "dioxin-like" PCBs in environmental samples from the steel industry

A method, previously used for determination of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), has been modified for quantitative analysis of "dioxin-like" polychlorobiphenyls (PCBs) in environmental samples from the steel industry. The existing sample clean-up procedure, involving liquid chromatography on multi-layered silica and Florisil columns, has been extended to include a third chromatography stage on a basic alumina stationary phase. The additional clean-up stage is required for PCB analysis in order to eliminate interferences from relatively large concentrations of saturated cyclic and aliphatic hydrocarbons. Samples were analysed for WHO-12 congeners using high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) and standard solutions of the method US EPA 1668A. Replicate analysis of method blanks revealed background contamination for PCBs 118, 105 and 77, which are generally abundant in ambient air. These contaminants were taken into account using a subtraction method. The entire procedure was validated by replicate analysis (N = 3) of a certified reference sediment. The RSD for each WHO-12 congener was below 15%, 13C12-labelled PCB internal standard recoveries were in the range 70-95%. A waste dust sample collected in the electrostatic precipitator of a UK sinter plant was analysed for determination of PCDD/Fs and WHO-12 PCBs and exhibited a PCDD/F I-TEQ of 148.5 +/- 21.2 ngkg(-1) and a WHO-TEQ of 7.2 +/- 1.5 ngkg(-1). WHO-12 congeners contributed only 4.6% to the overall TEQ and PCB 126 was the major congener contributing to the WHO-TEQ (96%). The contribution to the overall TEQ of the waste dust sample was mainly attributed to PCDF followed by PCDD, which accounted for 86.6% and 8.7% to the overall TEQ, respectively.     

Compound-specific isotopic and congener-specific analyses of polychlorinated biphenyl in the heat medium and rice oil of the Yusho incident

Compound-specific isotope analysis (CSIA) can be used to examine the source and transformation processes of organic pollutants in the environment. We performed a carbon stable isotope analysis of polychlorinated biphenyl (PCB) congeners in the PCB heat-transfer medium (heat medium) and the original Kanechlor-400 (KC-400, a commercial brand of PCBs) involved in the Yusho incident. The main purpose is to investigate whether isotope fractionation occurred in the rice oil deodorization process that caused the incident. The carbon isotope ratios (δ¹³C values) of the targeted PCB congeners ranged from ? 29.39 to ? 27.00‰ in the heat medium and from ? 28.77 to ? 27.05‰ in the original KC-400. No significant differences were found in the δ¹³C values, suggesting carbon isotope fractionation did not occur for the targeted PCB congeners in the heat medium when deodorization of rice oil occurred at temperatures above 200 °C. Furthermore, we also conducted a congener-specific analysis of 64 PCB congeners found in the heat medium and rice oil contaminated by it. The total PCB congener concentrations were 503 mg/g in the heat medium and 81 μg/g in the rice oil. The concentrations of the highly chlorinated congeners were significantly lower in the heat medium than in the original KC-400, and the compositional ratios of the lowly chlorinated congeners were relatively lower in the rice oil than in the heat medium. These results suggest that the PCB congener patterns gradually changed from that of the original KC-400 in the deodorization process and subsequent contamination into the rice oil. Thus, a combination of CSIA and congener-specific analysis is a new approach for investigating the changing PCB congener profiles in samples from the Yusho incident.     

Analysis of PCBs in sediments by glass capillary gas chromatography

The analysis of individual PCB components in river sediments with glass capillary gas chromatography was studied. For Aroclor 1242 a mean recovery of over 85 % was established. Decachlorobiphenyl contents obtained by perchlorination appear to be 1.1 to 3.7 times higher than total-PCB contents estimated with capillary GC. Besides reliable contents of individual PCBs the capillary method provides information about the composition of the PCB contamination in sediments and may be of use in the identification of PCB sources.     

Polychlorinated biphenyls (PCBs) in marine fishes from China: Levels, distribution and risk assessment

Muscle tissues of large yellow croakers (Pseudosciaena crocea) and sliver pomfret (Pampus argenteus) from nine coastal cities of East China including Dalian, Tianjin, Qingdao, Shanghai, Zhoushan, Wenzhou, Fuzhou, Quanzhou and Xiamen were analyzed for polychlorinated biphenyl (PCB) concentrations. Thirty-six PCB congeners were quantified in the fishes, of which 11 congeners were dioxin-like PCBs. The total PCB concentrations of the present study were at the low end of the global range, which may be related to the smaller usage and shorter consumption history of PCBs in China. PCBs 18, 29, 52, 66, 101, 104, 138, 153, 180 and 194 were the major constituents found in the fish samples. Regression analysis showed a strong positive correlation (R² = 0.800; p < 0.001) between total dioxin-like PCBs and total PCB concentrations, and that total PCB concentrations explain 80% of the variability in total dioxin-like PCB concentrations. Among the species investigated, significantly higher concentrations of total PCBs were found in croakers than in pomfrets, which may be attributed to their different feeding and living habits. No significant difference in total PCB concentrations among the cities was observed; principal component analysis (PCA) of PCB profiles indicated that PCB pollution came from similar sources in the sampling areas and that there may be other PCB sources in Dalian and Wenzhou. The calculated carcinogenic risks (CRs) from the two species based on a low consumption group and high consumption group were all greater than 10⁻⁶, suggesting that daily exposure to dioxin-like PCBs via fish consumption results in a lifetime cancer risk of greater than one in one million. In contrast, the hazard quotients (HQs) of noncancer risks were all less than unity.     

A review of the environmental fate and aquatic effects of a series of C4 and C8 oxo-process chemicals

Semipermeable membrane devices containing a neutral lipid triolein (triolein-SPMD) and conventional dichloromethane extraction were used to monitor the presence and concentrations of priority organic pollutants in a sewage treatment process in Beijing, China. Both samples gave similar information on the presence of target PCB congeners, PAHs, Organochlorine pesticides and substituted benzenes in sewage at all sites. After 20 days' sampling, the concentrations of contaminants in triolein of SPMD were much higher than those in dichloromethane extracts, which resulted in easier analysis, improved the detection limits, and increased the accuracy. Previous field mean sampling rates for SPMD were used to estimate concentrations of PCB congeners in sewage, which compared to their determined concentrations by dichloromethane extraction. The consistency and superiority of SPMD technology were proved for the detection of priority organic contaminants from sewage. Lower removal rates for PCB congeners and PAHs coincided with the persistence of them in environment. More attention should be paid to urban sewage treatment process adopting activated-sludge method, where priority organic pollutants might not be removed, even present higher concentrations after treatment.     

Determination of indicator polychlorinated biphenyls (PCBs) by gas chromatography–electron capture detector

An effective method for determination of indicator polychlorinated biphenyls (PCBs) has been validated using gas chromatography (GC) equipped with electron capture detector (ECD). The GC–ECD method was validated by determining the linear range (working range) for determination of the compounds, minimum detectable quantities (MDQ), the precision and accuracy of the method for the analysis of the compounds. MDQ obtained for the compounds ranges from 0.0005 to 0.002 ng. Indeed the method was found to be more sensitive as the number of chlorine atoms attached to the biphenyl increases. The precision and accuracy of the GC method validated ranges from 2.4% to 14.5% and −7.0% to 14.6% respectively. Coefficient of variation associated with the repeatability of the retention times and corresponding peak areas was found to be 0.0001–0.0007 for the retention times and 0.0014–0.059 for the peak areas. Percentage recoveries for the compounds were in the range of 95.7–101.0%. The validated method was then applied to determine levels of indicator PCBs in sediments sampled from eleven sampling points along the Lake Bosuntwi in Ghana and the highest PCB load of 19.17 ng g⁻¹ was recorded at Pipie No. 2. PCB 52 and PCB 101 were found to be the most ubiquitous indicator PCBs in the study area, both with 90.91% occurrence.     

Hair analysis: another approach for the assessment of human exposure to selected persistent organochlorine pollutants

Hair analysis was used for the assessment of exposure to organochlorine pollutants in specimens from Greece, Romania and Belgium. A simple method (using 3 N HCI as incubation reagent, liquid-liquid extraction with hexane/ dichloromethane (DCM), alumina/acid silica clean-up and GC-ECD/GC-MS analysis) was used for screening of specimens. The highest organochlorine load (up to 148 ng/g hair for the sum of PCB, DDT and hexachlorocyclohexane (HCH) isomers) was found in samples from a group of Greek women with past occupational exposure to pesticides. DDTs were the main organochlorine pollutants in Greek samples (up to 70%), while in Belgian hair samples their contribution was reduced to 40%. PCB mean concentration was higher in Belgian specimens (up to 14 ng/g hair). Lindane (y-HCH) was the main HCH isomer found in the samples (up to 82% in the Greek samples). Contribution of p,p'-DDT to the sum of DDTs was higher in Greek samples and indicates recent exposure to technical DDT. Similar PCB 153/sum PCBs ratios were found for each of the three countries suggesting similar sources of pollution with PCBs (mainly dietary). Artificially coloured hair samples were found to have lower, but not statistically significant concentrations of organochlorine pollutants than the non-coloured hair.