The influence of soil contamination on the concentrations of PCBs in milk in Siberia

Although atmospheric deposition is generally the dominant pathway of PCBs into agricultural food chains, soil ingestion by livestock can be important in some cases. The relationship between PCB levels in cow's milk and in pasture soil was studied in the Irkutsk region in Siberia where an historical atmospheric source(s) of PCBs has led to widespread contamination of soil. Milk samples were collected in spring and again in autumn from 18 different farms and analyzed for PCBs. Pasture soil samples were also collected and analyzed. The PCB concentrations in both milk and soil ranged over more than an order of magnitude between the farms. A good correlation was obtained between PCB levels in autumn milk and in soil. This together with a range of other evidence suggested that ingestion of pasture soil was the dominant source of the PCB contamination in the milk. The average soil ingestion rate was estimated to be 1700 g/d, which is at the upper end of values reported in the literature. This may be due to the arid summer climate or the animal husbandry practices in Siberia.     

Levels and trends of PCDD/Fs and PCBs in human milk in Finland

Word Health Organization, WHO/EURO, has coordinated two rounds of follow-up studies on levels of PCDDs, PCDFs, and PCBs in human milk which were analyzed as two pooled samples from each participating country, one from urban and the other one from rural area. Finland has taken part to both of those studies and we are now reporting results of all the second round randomly sampled human milk samples (84 samples) from Southern (20) and Eastern (64) Finland. The levels of PCDD/Fs and PCBs in human milk in Southern Finland were considerably higher than in Eastern Finland. The level of PCDD/Fs in human milk in Southern Finland was the same as in the Central Europe but the level in Eastern Finland was similar to levels in Norway and eastern parts of Europe. The concentrations of PCDD/Fs and PCBs showed a significant decrease from 1987 to 1994. Declining of PCDD/Fs and PCBs was 36 and 49% in primiparae mothers' milk, respectively. This decrease in concentrations of PCDD/F and PCB was slightly greater in Eastern than in Southern Finland.     

Concentration changes of PCDDs, PCDFs, and dioxin-like PCBs in human breast milk samples as shown by a follow-up survey

Breast milk is known to discharge dioxins from the human body. However, to date, no direct comparison has been made of the concentrations of dioxin analogues in breast milk obtained from identical population after successive deliveries. We present here follow-up survey results of PCDDs, PCDFs, and dioxin-like PCBs concentrations in human breast milk samples from 35 women living in Tokyo from whom samples had been obtained and analyzed to determine the corresponding concentrations in the past. The average concentrations of total PCDDs, PCDFs, dioxin-like PCBs were 8.5, 5.5, 11 TEQ pg/g fat for the first samples and 5.4, 4.0, 6.6 TEQ pg/g fat for the second samples, respectively. The degrees of reduction of total PCDDs and total dioxin-like PCBs were higher than that of total PCDFs because 1,2,3,7,8-PeCDD, 2,3,4,7,8-PeCDF and 3,3',4,4',5-PeCB (#126), which were the predominant congeners among PCDDs, PCDFs, and dioxin-like PCBs, respectively, had different degrees of reduction. Moreover we observed a significant increase of the concentrations of PCDDs, PCDFs, and dioxin-like PCBs in samples from three women in this follow-up survey, and the patterns of increased isomers differed among the three samples. It was conjectured that the increase of the concentrations was due mainly to dietary intake between deliveries. It is important for pregnant women to have a balanced diet to mitigate the exposure of infants to these chemicals.     

Levels of dioxins, furans and PCBs in human serum and milk of people living in Greece

In an attempt to evaluate the background levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), non-ortho, mono-ortho and indicator polychlorinated biphenyls (PCBs) in people living in an urban (Athens) and a rural (Kozani) area of Greece, blood serum and mother milk samples were analyzed. Analytical results are reported in this study. Statistically significantly differences were observed between regions, sexes and ages. Contamination levels in blood and human milk from Greece reported here are low compared to the previously reported dioxin data from other European countries and give no indication of particular health risk.     

Predicting dioxin-like PCBs soil contamination levels using milk of grazing animal as indicator

Dioxin-like PCBs (dl-PCBs) are ubiquitous persistent organic pollutants of recognized negative effects on human health. Assessing highly polluted areas should be an important public health issue. This study proposes to use the milk of grazing animals as a bioindicator of dl-PCB contamination in the environment. The hypothesis is that milk concentration of dl-PCBs are related to soil concentrations of these compounds, and that soils are generally reflective of a larger environmental issue of dl-PCB contamination. In this study, we evaluate the possibility of predicting soil concentrations using milk of sheep, cows and buffalos in a spatial model. For this purpose, samples of soil and milk collected in Campania (Italy) were introduced in a GIS platform to perform geostatistical analysis for building a simple predictive model. The ordinary least squares regressions (OLS) showed a statistically significant correlation (p < 0.05) between soil and milk contamination. However, this relationship was spatially variable. Thus, a geographically weighted regression (GWR) was performed, obtaining R² values of 0.91, 0.77 and 0.66 for sheep’s, buffalo’s and cow’s milk respectively. Assessed the mathematical relationships between the variables, new data was introduced to evaluate the performance of the model. Predictions of soil contamination with dl-PCBs using sheep’s, cow’s and buffalo’s milk showed a mean error of 23%, 25% and 36% respectively. According to these results the sheep’s milk can be considered the best bioindicator of dl-PCBs contamination among the three species. The results of this project evidence the potentialities of the proposed approach to assess bioindicator performance in a spatial predictive model.     

PCDDs, PCDFs, and PCBs concentrations in breast milk from two areas in Korea: body burden of mothers and implications for feeding infants

We determined breast milk concentration of polychlorinated dibenzo-p-dioxins (PCDDs)/polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) in 24 mothers living in Korea, and assessed the maternal body burden based on PCDDs/PCDFs and PCBs concentrations in breast milk and an infant intake rate through breast-feeding based on their concentration in breast milk. PCDDs/PCDFs and PCBs levels in breast milk from primipara mothers were found to be higher than those from multipara mothers. For total PCDDs/PCDFs TEQ level, 2,3,4,7,8-PeCDD was the predominant congener, and the proportion of 2,3,7,8-TCDD was less than 3% of total PCDDs/PCDFs TEQ level. For PCBs TEQ level, PCB-126 was the predominant congener. Maternal body burden levels of PCDDs/PCDFs and PCBs based on their concentrations in breast milk were 268-622 TEQ ng. The daily dioxin intakes of mothers were predicted to be 0.78-2.18 TEQ pg/kg/day for PCDDs/PCDFs and 0.34-0.66 TEQ pg/kg/ day for PCBs. For the first year, the body burden of an infant was predicted to be 212 TEQ ng and the daily intake of an infant was predicted to be 85 TEQ pg/kg/day, assuming the mean dioxin-related compounds concentration (27.54 TEQ pg/g fat).     

PCDD/Fs and dioxin-like PCBs in human milk and estimation of infants' daily intake: a review

This paper reviews the recent scientific literature on PCDDs, PCDFs and dioxin-like PCBs in human milk. All the papers reporting levels of these contaminants in human breast milk published from January 2000 to January 2009 and available on the www.sciencedirect.com web site were identified and included. The aim was (1) to study levels of PCDDs, PCDFs and PCBs in human milk in mothers from different geographical areas and assess infant exposure to these contaminants; (2) to study the effect of variables such as the mother’s age, number of deliveries, dietary and smoking habits and her own nutrition in infancy, and the environment, on levels of the contaminants in breast milk; (3) to study time patterns, and (4) to identify data gaps.     

Serum PCBs and organochlorine pesticides in Slovakia: age, gender, and residence as determinants of organochlorine concentrations

We measured organochlorine concentrations of 15 polychlorinated biphenyl congeners and six organochlorine pesticides (PCB28, 52, 101, 123(+149), 118, 114, 153, 105, 138(+163), 167, 156(+171), 157, 180, 170, 189, alpha-, beta-, gamma-HCH, HCB, p,p'-DDT and p,p'-DDE) in 2047 subjects from contaminated and background areas of eastern Slovakia. Data were collected in 2001 and analyzed by high-resolution gas chromatography with electron capture detection in 2002-2003. Elevated levels persist in subjects from Michalovce district, site of former production facility, after almost 20-years since the end of the PCB manufacturing. Sum of 15 PCB congeners was 3105 ng/g of lipid in the Michalovce district versus 871 ng/g of lipid for subjects from the background districts of Svidnik and Stropkov. Relatively high concentration in children from the Michalovce district, sum PCB = 766 ng/g of lipid versus 372 ng/g of lipid in children from background area suggest ongoing exposure from environmental reservoirs and contaminated food. Consistent differences between genders in both contaminated and background areas are reported here. Levels in males are about 20% higher in both districts. Levels of organochlorine pesticides, particularly of DDT metabolite DDE and hexachlorobenzene are also elevated in the Michalovce district, reflecting intensive use of pesticides in agriculture in the past. About 30% decrease in serum organochlorine levels was observed in comparison with our earlier samples collected in 1998. These results suggest that contamination with PCBs still remains a source of relatively high environmental exposure for subjects in the Michalovce district.     

Longitudinal increases in PCDD/F and dl-PCB concentrations in human milk in northern China

There is a dearth of information on the temporal changes in polychlorinated dibenzodioxin/furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) contamination, in both environmental and biological specimens, in China. We compared the concentrations of PCDD/Fs and dl-PCBs in human milk collected in Shijiazhuang, Hebei Province, in northern China in 2002 (n=30) and 2007 (n=20). The level of PCDD/Fs and dl-PCBs showed an increasing trend. The mean concentrations of PCDD/Fs plus dl-PCBs were 4.47 TEQ pg g(-1) fat and 6.24 TEQ pg g(-1) fat in human milk from Shijiazhuang in 2002 and in 2007, respectively. Based on statistical analysis of questionnaire data collected by in-person interviews with mothers, we found positive correlations between consumption of sea fish and PCDFs. The PCDDs, PCDFs, PCDD/Fs, and PCDD/Fs plus dl-PCBs levels in individuals consuming greater amounts of sea fish were higher than those consuming less sea fish, both with and without adjustments for potential confounding factors. Among 17 congeners of PCDD/Fs, the 2,3,7,8-TCDF, 1,2,3,7,8-PeCDF, 2,3,4,7,8-PeCDF, 1,2,3,4,7,8-HxCDF, 1,2,3,6,7,8-HxCDF, and 2,3,4,6,7,8-HxCDF congener concentrations in 2007 increased 134%, 55%, 53%, 57%, 65% and 130% when compared to 2002 levels, respectively. The 2007 dl-PCB congener levels were greater than those of the 2002 samples, with the exception of PCB81 and PCB77. Specifically, PCB105, PCB114, PCB118, PCB123 and PCB156 had increased greater than twofold from 2002 to 2007. Continuous surveillance of PCDD/F and dl-PCB levels in human milk is needed to accurately evaluate both environmental contamination and the human health risk to neonates in China.     

Occurrence of PCBs, PCDD/Fs, PBDEs and DDTs in Spanish breast milk: enantiomeric fraction of chiral PCBs

Concentrations and congener specific profile of DDTs, PCBs and PCDD/Fs have been determined in a number of Spanish breast milk samples. The concentrations found indicate a decreasing tendency compared to previous data from the 1990s. Mean concentrations of 238 ng/g fat weight, 111 ng/g fat weight and 82.1 pg/g fat weight were found for DDTs, PCBs and 2,3,7,8-PCDD/Fs, respectively. When the WHO-TEQs were calculated, PCDD/Fs was the family contributing with the highest percentage to the total (62-84%), followed by the non-ortho PCBs (10-25%) and the mono-ortho PCBs (5-24%). The congener specific accumulation patterns found were comparable to those reported in other studies in industrialised countries. In addition, the levels of 9 PBDEs congeners have been also determined in the breast milk samples. The concentrations ranged from 0.04 to 1.38 ng/g fat weight. The enantiomeric enrichment of a number of chiral PCBs in the breast milk samples, including congeners 84, 91, 95, 132, 135, 149, 171, 174, 176 and 183, has also been studied, for some of them for the first time in this matrix.     

Biomonitoring perfluorinated compounds in Catalonia,Spain: concentrations and trends in human liver and milk samples

Background, aim and scope  

Perfluorinated compounds (PFCs) are global environmental pollutants that bioaccumulate in wildlife and humans. Laboratory experiments have revealed toxic effects such as delayed development, humoral suppression, and hepatotoxicity. Although numerous human blood levels have been reported, little is known about distribution in the human body. Knowledge about PFC distribution and accumulation in the human body is crucial to understanding uptake and subsequent effects as well as to conduct risk assessments. The present study reports PFC levels in human liver and breast milk from a general population living in Catalonia, Spain. Liver and milk levels are compared to previously reported levels in blood from the same geographic area as well as to other existing reports on human liver and milk levels in other countries.     

PCDD, PCDF, AND PCB concentrations in human milk from two areas in Finland

Concentrations of 17 toxic 2,3,7,8-chlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and of 36 polychlorinated biphenyl congeners (PCBs) were analyzed from 167 randomly sampled human milk samples from Southern (77 samples) and Eastern (90) Finland. The level of PCDD/Fs and PCBs in human milk in Southern Finland was about 25% higher than those from Eastern Finland. The level of PCDD/Fs in human milk in Finland was the same as in Sweden, 30–50 % lower than in milk from Central Europe but about 45% higher than values from Norway or Russia. The PCB concentrations in Southern Finland were at the same level as in the Netherlands, and in Eastern Finland at the same level as in Norway. The levels of PCDD/Fs and PCBs decreased with increasing number of children: the third child was exposed to about 70% of the amount of PCDD/Fs and PCBs as compared with the first child, and the eighth to tenth child to about 20%. The congener patterns of PCDD/Fs and PCBs in Finnish human milk were similar to the countries of Central Europe, however, the levels of penta- and heptachlorinated furans were slightly higher than in milk from other countries.     

Generator column determination of aqueous solubilities for non-ortho and mono-ortho substituted polychlorinated biphenyls

Aqueous solubilities of four non-ortho and eight mono-ortho substituted PCBs were determined using a generator-column technique followed by subsequent off-line GC/ECD analysis of the aqueous solutions. The method is based on pumping water through a column containing glass beads coated with the congener being studied and has been used to measure solubilities at room temperature. The method circumvents many of the experimental difficulties encountered with the traditional shake-flask system. Aqueous solubility of 3,3′,4,4′-tetrachlorobiphenyl determined by this procedure is compared with data obtained from the shake-flask method and the computational method. The precision of replicate measurements is better than ±6.5%. Aqueous solubilities determined for 12 congeners ranged from 6.07 × 10⁻¹¹ to 4.47 × ⁻⁹ mol/L and generally decreased with molecular weight and increased with degree of ortho-chlorine substitution within a molecular-weight class.     

Relationship between two consecutive lactations and fat level in persistent organochlorine compound concentrations in human breast milk

An attempt was made to understand how consecutive deliveries and the following lactations have an impact on the organochlorine compound levels detected in human milk. The other goal of the study was to check for a possible dependence between fat content and the levels of the studied compounds in milk samples from the same lactations. 199 milk samples were examined for the presence of p,p'-DDT, p,p'-DDE, p,p'-DDD, alpha-, beta-, gamma-HCH and sigmaPCBs. Moreover, in 87 milk samples the fat content was additionally determined. This study has indicated that, for the mother with a shorter interval between lactations, mean concentrations of the examined compounds were higher in the milk of the first lactation than that of the second. For the other donor whose second lactation began after 2 years, the mean levels of HCB, beta-HCH, p,p'-DDD, and PCBs in her milk were higher during the first lactation. At the same time, the concentrations of p,p'-DDT and p,p'-DDE after the second delivery were slightly higher. The correlation coefficients between the two data sets (fat content in milk, concentrations of the compounds studied in milk) showed no interrelationship between them.     

Dioxin-like and non-dioxin-like PCBs in human serum of Slovak population

In the present study, non-ortho, mono-ortho and other ortho-substituted PCB congeners were analysed in individual blood serum samples taken from healthy adults (196 males and 119 females) in the polluted area of the Michalovce district and in the background area of the Stropkov/Svidnik districts in Eastern Slovakia by high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS). The samples from general population living in villages and towns of two regions were taken between August 2001 and February 2002 within the project of the EC's 5th Framework Programme (PCBRISK, ). The medians of dioxin-like PCBs (dl-PCBs)--expressed as TEQs on lipid basis--of all males (24.7 pg g(-1) lipid) and females (21.4 pg g(-1) lipid) were comparable, but there was a significant difference between both of the areas studied. In the district of Michalovce, the medians of males (47.3 pg g(-1) lipid) and females (41.1 pg g(-1) lipid) were 2.3 times higher than in the area of the Stropkov/Svidnik districts. The medians of total non-dioxin-like PCB concentration were 1,835 and 1,033 ng g(-1) lipid in males and females, respectively. The data show a trend toward higher concentrations of both dl- and non-dioxin-like PCBs in the older age groups. The substantial increase was observed for the 60+ age group. PCB-126 was the most abundant non-ortho congener. PCBs-118 and 156 were the predominant mono-ortho congeners. They were quantitated in all samples analysed. Congeners 153, 138(+163), 180 and 170(+190) were the main contributors to total non-dioxin-like PCB concentrations. Mean mutual ratio HexaCBs:HeptaCBs:OctaCBs in the non-dioxin-like group was 37:50:1. The results of this study represent the overall information about the congener distribution of dioxin-like and non-dioxin-like PCBs in human serum blood of adult Slovaks.     

Comparison of organochlorine compound concentrations in colostrum and mature milk

Human breast milk represents the best choice for the nutrition of infants. It is often used for monitoring human exposures to environmental chemicals. Uniquely suited to meet human biological needs, breast milk composition, especially fat content, changes significantly with time from delivery. With the aim to compare the concentration of organochlorine compounds (OCs) in colostrum versus mature milk, we obtained samples of fourth-fifth day postpartum milk (colostrum) and day-14 postpartum milk (mature milk) from 12 women enrolled in the project "Early Childhood Development and PCB Exposure in Slovakia". The concentrations of selected organochlorine pesticides and congeners of polychlorinated biphenyls (PCBs) were measured using gas chromatography with electron capture detection and reported on lipid adjusted basis. No significant differences were found between organochlorine levels in colostrum and those in mature milk samples. A very close correlation was found between the concentrations of organochlorine compounds in colostrum and mature milk (Spearman correlation coefficient r=0.94-0.98 for PCBs, and r=0.85-0.99 for organochlorine pesticides, p<0.001 for all compounds). The present study concludes that the use of colostrum samples provides a close estimate of the child's exposure to OCs in the early neonatal period and demonstrates that, despite the lower fat content, colostrum specimens are adequate to conduct OC analyses.     

Methods for the analysis of PCBs in human food, faeces and serum.

A method was developed to determine trace concentrations of a range of individual PCB congeners in biological samples (serum, food and faeces) using GC-MS, to prepare a mass balance of PCBs in humans. A simple method for the analysis of PCBs in human serum, which excluded an extraction step, was first employed. Results indicated that the recoveries of 13C12 PCB spikes were variable. A soxhlet extraction step was added and was found to be efficient and reproducible. A quality control routine and method validation results are presented. In batch tests of the methods presented it was found that the serum analysis method gave within batch mean 13C12 spike recoveries of 98-120% and standard deviations between 6 and 20%. The food/faeces analysis method gave within-batch mean 13C12 spike recoveries of 88-100%, and within batch standard deviations between 4 and 12%. The batch to batch mean recovery for serum analysis was 100%, with an RSD of 9% for high spikes and 10% for low spikes. For food/faeces analysis the batch to batch average recovery was 110%, with an RSD of 5% for high spikes and 9% for low spikes.     

A systematic review and meta-analysis of lead and cadmium concentrations in cow milk in Iran and human health risk assessment

The aim of the current research was to systematically review and summarize the studies that evaluated the concentration of lead (Pb) and cadmium (Cd) in cow milk in different regions of Iran and to perform a meta-analysis of the findings. Moreover, the non-carcinogenic and carcinogenic risks of Pb and Cd through milk consumption in adult and child consumers were assessed. As a result of a systematic search in the international and national databases between January 2008 and October 2018, 17 reports involving 1874 samples were incorporated in our study for meta-analysis. The pooled concentrations of Pb and Cd were estimated to be 13.95 μg mL−1 (95% CI 9.72–18.11 μg mL−1) and 3.55 μg mL−1 (95% CI − 2.38–9.48 μg mL−1), respectively, which were lower than the WHO/FAO and national standard limits. The estimated weekly intake (EWI) of Pb and Cd through consuming milk was 16.65 and 7 μg day−1 for adults of 70 kg and 45 and 34 μg day−1 for children of 26 kg, respectively, which was well below the risk values set by Joint FAO/WHO Expert Committee on Food Additives (JECFA). The maximum target hazard quotient values (THQs) of Pb and Cd were 5.55E−5 and 5.55E−5 for adults and 5.55E−5 and 5.55E−5 for children, respectively, which were lower than 1 value, suggesting that Iranian consumers are not exposed to non-carcinogenic risk through consuming milk. Moreover, the incremental lifetime cancer risk (ILCR) of Pb estimated to be 2.96E−04 in adults and 1.0E−03 in children, indicating that consumers in Iran are at threshold carcinogenic risk of Pb through consuming milk (ILCR > 10−4). Therefore, planning and policy making for the sustainable reduction of these toxic metals in milk, particularly in industrial regions of Iran, are crucial.     

Assessing the human health effects of PCBs

Toxic effects can be induced in experimental animals by high doses of pure PCBs, and in man by PCDF-contaminated PCB. In order to assess the effects of ordinary, uncontaminated PCB on man, a group of capacitor workers who had direct occupational exposure to Aroclors 1254, 1242, and 1016 during the period 1946 to 1977 has been under medical surveillance since 1976. This group presented some indications of non-AhR-mediated microsomal enzyme induction during the period of direct exposure, but no chloracne or increased cancer mortality. Multiple regression studies revealed no significant associations between lipid PCB levels and clinical indicators of hepatotoxicity, hypertension, or pulmonary impairment.