PCDD/F and non-ortho PCB concentrations in adipose tissue of individuals living in the vicinity of a hazardous waste incinerator

To assess the influence of a new hazardous waste incinerator (HWI) on public health, a preoperational monitoring program was established during the period of construction. In this study, the levels of polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) accumulated in adipose tissue of 15 autopsied subjects living in the area under potential impact of the HWI were determined after approximately 3 years of regular operations in the facility. The non-ortho PCBs 77, 126 and 169 were also determined. PCDD/F concentrations ranged between 1.5 and 41 pg WHO-TEQ/g fat (2.4 and 72 WHO-TEQ/g fat, respectively, including PCBs), with a mean value of 11 pg WHO-TEQ/g fat and a median value of 7.4 pg WHO-TEQ/g fat (22 and 13 WHO-TEQ/g fat, respectively, including PCBs). In the baseline study, the mean level of PCDD/Fs was 36 pg WHO-TEQ/g fat (61 pg WHO-TEQ/g fat, including non-ortho PCBs 77, 126 and 169), which means a reduction of 70% (64% including PCBs). This notable reduction is in accordance with the important decrease observed in recent years in PCDD/F intake through the diet. The current concentrations of PCDD/Fs in human adipose tissue, as well as recent data on PCDD/F levels in plasma and breast milk of subjects living in the vicinity of the same HWI, indicate that there is not any additional significant exposure to PCDD/Fs for this population.     

Monitoring dioxins and furans in a population living near a hazardous waste incinerator: levels in breast milk

In this study, the concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDFs) in breast milk from mothers living in the vicinity of a new hazardous waste incinerator (HWI) were determined. Monitoring was performed after three years of regular operations in the facility and the present results were compared with baseline concentrations obtained in a pre-operational program. PCDD/PCDF levels were determined by HRGC/HRMS in 15 samples. In the present study, PCDD/PCDF concentrations ranged from 4.9 to 39.9 pg I-TEQ/g fat (5.1-46.8 pg WHO-TEQ/g fat), with a median value of 7.7 pg I-TEQ/g fat (9.1 pg WHO-TEQ/g fat). In the baseline survey, PCDD/PCDF concentrations ranged between 5.9 and 17.1 pg I-TEQ/g fat, with a median value of 11.7 pg I-TEQ/g fat. In relation to this, a percentage of reduction of 34.2% was noted. This decrease is in agreement with the relevant reduction found in the dietary intake of PCDD/PCDFs between both surveys. The results of the present study, as well as other recent environmental and biological data, indicate that living in the vicinity of this HWI should not mean additional health risks due to PCDD/PCDFs for the general population.     

Concentration of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and dioxin-like PCBs in human adipose tissue from Turkish men

There is no previous report from Turkey on chemically determined polychlorinated dibenzo-para-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (PCBs) in human tissues expressed as World Health Organization (WHO) toxic equivalents (TEQs). The objective of this study was to determine the occurrence of PCDDs/Fs, and dioxin-like PCBs in the general adult Turkish population. For this reason we measured adipose tissue concentrations of PCDDs/Fs and dioxin-like PCBs in 23 Turkish men living in Ankara,Turkey in 2004. PCDD/F concentrations ranged between 3.2 and 19.7 pg WHO-TEQ/g fat (5.34 and 42.7 WHO-TEQ/g fat, respectively, including dioxin-like PCBs). The mean concentrations of WHO(PCDD/F)-TEQ and WHO(PCB)-TEQ were 9.2 and 6.67 pg/g on a lipid basis , respectively. Samples were analyzed for PCDD/F and twelve dioxin-like PCB congeners using high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS). This study is very important since it is the first report on PCDDs/Fs and dioxin-like PCB contamination in human adipose tissue from Turkey.     

Polychlorinated dibenzo-p-dioxins, dibenzofurans and polychlorinated biphenyls levels in human breast milk from different regions of Turkey

Human breast milk offers the optimal nutrition for all infants and have been widely used in biomonitoring programs to assess human exposure to lipophylic environmental contaminants such as polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF) and polychlorinated biphenyls (PCB). There are no previous reports from Turkey on chemically determined levels of PCDDs, PCDFs, and PCBs in human breast milk expressed as World Health Organization (WHO) toxic equivalents (TEQ). To get an overview of the levels of these contaminants in Turkish human milk, samples from 51 Turkish women living in the Ankara, İstanbul, Antalya, Kahramanmaraş, and Afyon provinces were analyzed by high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) throughout 2007. The mean concentrations of WHO_PCDD/F-TEQ and WHO_PCB-TEQ of all samples from the five regions were 7.5 and 3.1 pg g⁻¹ on a lipid basis, respectively. PCDD/F concentrations ranged between 0.78 and 29.3 pg WHO-TEQ g⁻¹ fat (1.7 and 36.2 pg WHO-TEQ g⁻¹ fat, respectively, including PCB). Of the five studied locations, the lowest levels of ∑TEQs (PCDD/F + PCB) were found in the Afyon (6.8 pg WHO-TEQ g⁻¹ fat) and the highest in the Antalya (15.6 pg WHO-TEQ g⁻¹ fat) province. The results have been discussed in terms of regions and PCDD/F and PCBs for which analyses had been made. The mean levels of PCDD/Fs and PCBs in Turkish human milk are comparable to that found in other countries.     

PCDD/F levels in plasma of a belgian population before and after the 1999 belgian PCB/DIOXIN incident

We evaluated the impact of the 1999 Belgian dioxin incident on the blood plasma polychlorinated dibenzo-p-dioxin (PCDD) and polychlorinated dibenzofuran (PCDF) levels among 232 Belgian blood donors (74% men, mean age 47 years). The Red Cross made plasma samples from before the incident of these donors available. A second plasma sample was collected during the second half of 2000. The sum of the 17 PCDD/F congeners was significantly lower in 2000 compared to 1998 (417 pg/g fat versus 445 pg/g fat, respectively). This could be completely attributed to the significant decrease of OctaCDD (301 pg/g fat in 2000 versus 277 pg/g fat in 1998). Moreover a slight but significant decrease was observed for 2,3,7,8-TetraCDF and for 1,2,3,4,6,7,8-HeptaCDF. 1,2,3,7,8-PentaCDF and 2,3,4,7,8-PentaCDF however showed a slight but significant increase (respective levels in 1998 were 0.004 and 14.5 pg/g fat compared to 0.006 and 17.9 pg/g fat in 2000). Given their significantly higher presence in incident related food samples this increase can be attributed to the food contamination episode. However, the total toxicity remained unchanged (22.9 in 1998 versus 23.1 pg WHO-TEQ/g fat, p>0.05). Moreover the observed congener profiles and the total PCDD/F levels were similar to those of other European non-occupationally exposed populations. In conclusion, the 1999 PCB/dioxin incident was traceable in the plasma profiles (rise of the two specific PCDF congeners), but comparison of the results for both years indicates that the changes were too small to cause an adverse public health effect.     

Dietary exposure to PCDD/PCDFs by individuals living near a hazardous waste incinerator in Catalonia, Spain: temporal trend

The levels of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) were measured in foodstuffs randomly acquired in July 2006 in various locations of Tarragona County (Catalonia, Spain), which are near a hazardous waste incinerator (HWI). A total of 35 composite samples, belonging to various food groups (vegetables, pulses, cereals, fruits, fish and seafood, meat and meat products, eggs, milk, dairy products, and oils and fats) were analyzed by HRGC/HRMS. The dietary intake of PCDD/PCDFs was subsequently determined and compared with a previous survey performed in 2002. For calculations, recent data on consumption of the selected food items were used. Total dietary intake of PCDD/PCDFs for the general population of Tarragona County was estimated to be 27.81 pg WHO-TEQ/day, value notably lower than that found in the 2002 study, 63.80 pg WHO-TEQ/day. Fish and seafood (28%), oils and fats (22%), eggs (17%), and dairy products (11%) were the most important contributors to this intake, while pulses (1%), milk (2%), vegetables (3%) and fruits (3%) showed the lowest contribution to total WHO-TEQ. The current PCDD/PCDF intake is also considerably lower than the intake estimated in 1998 for the population of the same geographical area, 210.1 pg I-TEQ/day, when a baseline study was carried out during the construction of the HWI. The present intake is also compared with the dietary intakes of PCDD/PCDFs recently (2006-2007) reported for a number of regions and countries.     

PCDD/F levels in food and canteen meals from southern Germany

Analysis of food samples collected in 1997 and 1998 in Bavaria, Germany showed that PCDD/F levels in food of animal origin, with the exception of fish, have decreased to low levels way below 1 pg I-TEQ/g fat. Lowest PCDD/F contents were found in pork (mean: 0.27 pg I-TEQ/g fat) followed by poultry and cow's milk (mean: approx. 0.5 pg I-TEQ/g fat). Average contamination levels determined in beef and eggs lay in the range from 0.7 to 0.8 pg I-TEQ/g fat. PCDD/F levels in fish were clearly higher than levels in meat, milk and egg samples (mean: 5.6 pg I-TEQ/g fat). Comparison of topical levels with former results from Bavaria show that the recently detected decline of contamination of food has continued during the past few years. In addition to investigations of unprepared food, we analysed prepared canteen meals over a period of 1 year. The average PCDD/F level found in canteen food (0.37 pg I-TEQ/g fat) was in good conformity with determined PCDD/F levels in unprepared food regarding the estimated fat composition of prepared meals. The average consumption of fat per meal via canteen food was 21.1 g and the average PCDD/F intake per meal was 7.6 pg I-TEQ. On the supposition that determined PCDD/F levels in canteen food on fat basis are representative of total fat consumed by humans (102 g fat/day), the daily PCDD/F intake would amount to a mean value of 36.7 pg I-TEQ corresponding to 0.52 pg I-TEQ/kg body weight.     

Concentrations of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in milk of women from Catalonia, Spain

In this study, the concentrations of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in milk from women living in the vicinity of a new hazardous waste incinerator (HWI) in Catalonia, Spain, were determined. The study was performed after 4 years of regular operations in the facility and the present PCB levels were compared with baseline concentrations obtained in a pre-operational program. PCBs and PBDEs levels were determined by HRGC/HRMS in 15 samples. In the present study planar PCBs ranged from 1.3 to 6.3 pg WHO-TEQ/g fat with a mean value of 3.8 pg WHO-TEQ/g fat. After adding dioxin-like mono-ortho-PCBs the total PCB-TEQ concentrations ranged from 3.8 to 13.3 pg WHO-TEQ/g fat (mean value: 8.7 pg WHO-TEQ/g fat). A comparison of the current data with those obtained in the baseline study showed significant decreases for both planar and total WHO-TEQ of PCBs: 47.9% and 44.6%, respectively. PCB concentrations in milk of women living in urban zones were higher than those living near industrial areas (10.1 and 7.4 pg WHO-TEQ/g fat, respectively). Mean PBDE concentrations were 2.2 and 2.5 ng/g fat for women living in urban and industrial zones, respectively. Dietary intake of PCBs and PBDEs for a standard adult woman samples were 898 and 843 ng/day for PCBs, and 72 and 63 ng/day for PBDEs, for residents in urban and industrials areas, respectively. This study suggests that dietary intake is more relevant for human exposure to PCBs and PBDEs than living near the HWI.     

PCDD/F concentrations in milk of nonoccupationally exposed women living in southern Catalonia, Spain

Concentrations of 17 toxic 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) have been determined in pooled samples of breast milk from 15 mothers living in two residential areas (Tarragona downtown and an industrial area) in the vicinity of a new hazardous waste incinerator (HWI), now under construction in Tarragona (southern Catalonia, Spain). PCDD/Fs in human milk samples ranged between 5.9 and 17.1 pg I-TEQ/g fat (162-498 pg I-TEQ/l), with a mean value of 11.8 pg I-TEQ/g fat (310.8 pg I-TEQ/l). The percentages of fat ranged between 1.53 and 3.52. Although PCDD/F levels in milk from mothers living in the industrial area were found to be slightly higher than those observed in women living Tarragona downtown, most differences did not reach the level of statistical significance. In general terms, PCDD/F concentrations in human milk (pooled) samples of mothers living in the area of Tarragona are similar or lower than those previously reported for most industrialized countries.     

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) in breast milk of first-time Irish mothers: impact of the 2008 dioxin incident in Ireland

The 2008 dioxin incident in Ireland resulted in elevated concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) in Irish pork and pork products, due to the consumption of contaminated animal feed by pigs. In order to investigate any resulting impact on the Irish population, these contaminants were measured in pooled breast milk samples from 109 first-time mothers, collected in 2010. A comparison of the results with similar data from 2002 revealed generally lower concentrations of PCDD/Fs and dioxin-like PCBs in the 2010 samples, confirming the declining trend reported by many authors. Contaminant concentration levels for both 2002 and 2010 were generally slightly lower than those reported internationally, with a mean combined PCDD/F and PCB WHO-TEQ of 9.66 pg g⁻¹ fat, for an overall pooled sample of milk from 2010. An apparent slight increase in PCDFs was observed between 2002 and 2010 (from 2.73 pg WHO-TEQ g⁻¹ fat to 3.21 pg WHO-TEQ g⁻¹ fat), with the main contributory congener being 2,3,4,7,8-PentaCDF. While it cannot be totally discounted that the slight increase in 2,3,4,7,8-PentaCDF and in the overall PCDF WHO-TEQ in breast milk could be attributable to consumption of Irish pork during the 2008 incident, we consider that it is more likely that this was due to other factors, including the predominantly urban/industrial sampling locations for the 2010 samples, compared to 2002.     

Levels of PCDD/Fs,PCBs and PBDEs in breast milk of women living in the vicinity of a hazardous waste incinerator: Assessment of the temporal trend

The concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) were determined in breast milk from women living in the vicinity of a hazardous waste incinerator (HWI) in Catalonia, Spain. The results were compared with the levels obtained in previous surveys carried out in the same area in 1998 (baseline study), 2002 and 2007. The current total concentrations of 2,3,7,8-chlorinated PCDD/Fs in breast milk ranged from 18 to 126 pg g⁻¹ fat (1.1–12.3 pg WHO₂₀₀₅-TEQ_PCDD/F), while the total levels of PCBs ranged from 27 to 405 pg g⁻¹ fat (0.7–5.3 pg WHO₂₀₀₅-TEQ_PCB). In turn, PBDE concentrations (sum of 15 congeners) ranged 0.3–5.1 g g⁻¹ fat, with a mean value of 1.3 ng g⁻¹ fat. A general decrease in the concentrations for PCDD/Fs, both planar and total PCBs, and PBDEs in breast milk was observed. The levels of PCDD/Fs, PCBs, and PBDEs in milk of women living in urban zones were higher than those corresponding to industrial zones (41%, 26%, and 8%, respectively). For PCDD/Fs and PCBs, the current decreases are in accordance with the reduction in the dietary intake of these pollutants that we have also observed in recent studies carried out in the same area of study.     

Levels of PCDDs, PCDFs and PCBs in Belgian and international fast food samples

Congener-specific analyses of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) were performed on twenty-eight non-pooled fast food samples collected in Belgium, Switzerland, Czech Republic, United States of America and Australia. PCDD/F and PCB concentrations for the four investigated types of meals were very low. PCDD/F values ranged from non-detected to 1.40 pg WHO-TEQ/g fat and from 0.79 to 2.08 pg WHO-TEQ/g fat for lower and upper bound, respectively. Major contributors to the PCDD/F TEQ were 1,2,3,4,7,8-HxCDD, 1,2,3,6,7,8-HxCDD, 2,3,7,8-TCDF and 2,3,4,7,8-PeCDF. The relative contribution of PCBs to the total TEQ was 68%. For adults, an average estimated intake was 6.7 pg WHO-TEQ/kg bw/month, including consumption of all types of analyzed meals, representing 9.5% of the PTMI. For child, a value of 14.5 pg WHO-TEQ/kg bw/month was obtained, representing 20.6% of the PTMI.     

Concentrations of PCDD/PCDFs in plasma of subjects living in the vicinity of a hazardous waste incinerator: follow-up and modeling validation

In 2007, the concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDFs) were determined in plasma of non-occupationally exposed subjects living near the only hazardous waste incinerator (HWI) in Spain (Constantí, Tarragona County, Catalonia). These data were compared with the levels found in two previous surveys performed in 1998 (baseline) and 2002. The current mean PCDD/PCDF concentration in plasma was 9.36pg I-TEQg(-1) of lipid (range: 1.76-23.44pg I-TEQg(-1) of lipid). It means a significant reduction of the mean PCDD/PCDFs levels in plasma in comparison to the concentrations found in 1998 and 2002 (27.01 and 15.70pg I-TEQg(-1) of lipid, respectively). This important decrease agrees well with the notable reduction in the dietary intake of PCDD/PCDFs recently noted for the population of the same area (210.1pg I-TEQd(-1), 63.8pgWHO-TEQd(-1), and 27.8pgWHO-TEQd(-1), in 1998, 2002 and 2007, respectively). The current data were also used to predict theoretical PCDD/PCDF concentrations in plasma by executing a single-compartment empirically-based pharmacokinetic model on the basis of the daily intake of these pollutants by the local population.     

Environmental impact of a new hazardous waste incinerator in Catalonia,Spain: PCDD/PCDF levels in herbage samples

In April 1996 and 1998, the concentrations of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) were determined in 40 herbage samples collected in the neighborhood of a hazardous waste incinerator (HWI) under construction in Constanti (Catalonia, Spain). In April 2000, 20 months after the HWI began operating, herbage samples were again collected at the same sampling points in which samples had been taken in the previous surveys. PCDD/F concentrations ranged between 0.13 and 0.65 ng I-TEQ/kg (dry matter), with a median and mean values of 0.29 and 0.32 ng I-TEQ/kg (dry matter), respectively. The results were compared with those obtained in the 1996 (median, 0.53 ng I-TEQ/kg; mean, 0.61 ng I-TEQ/kg) and the 1998 (median, 0.23 ng I-TEQ/kg; mean, 0.31 ng I-TEQ/kg) surveys. While in the period 1996-1998 a significant decrease (49%, P < 0.001) in the mean PCDD/F levels was noted, in the period 1998-2000 an increase of 3% (P > 0.05) was found in the concentrations of PCDD/Fs. The analysis of the results suggests two potential hypotheses: either the emissions of PCDD/Fs from the HWI are not negligible, or the current PCDD/F emissions from other sources near the HWI remained at similar levels to those reached in 1998. Anyhow, an exhaustive evaluation of the present data shows an absence of notable PCDD/F contamination by the HWI in the area under its direct influence. It seems also probable that the decline in the atmospheric levels of PCDD/Fs due other emission sources of PCDD/Fs in this area is currently stopped.     

High average daily intake of PCDD/Fs and serum levels in residents living near a deserted factory producing pentachlorophenol (PCP) in Taiwan: influence of contaminated fish consumption

An abandoned pentachlorophenol plant and nearby area in southern Taiwan was heavily contaminated by dioxins, impurities formed in the PCP production process. The investigation showed that the average serum PCDD/Fs of residents living nearby area (62.5 pg WHO-TEQ/g lipid) was higher than those living in the non-polluted area (22.5 and 18.2 pg WHO-TEQ/g lipid) (P<0.05). In biota samples, average PCDD/F of milkfish in sea reservoir (28.3 pg WHO-TEQ/g) was higher than those in the nearby fish farm (0.15 pg WHO-TEQ/g), and Tilapia and shrimp showed the similar trend. The average daily PCDD/Fs intake of 38% participants was higher than 4 pg WHO-TEQ/kg/day suggested by the world health organization. Serum PCDD/F was positively associated with average daily intake (ADI) after adjustment for age, sex, BMI, and smoking status. In addition, a prospective cohort study is suggested to determine the long-term health effects on the people living near factory.     

Levels and congener distributions of PCDDs,PCDFs and non-ortho PCBs in Belgian foodstuffs--assessment of dietary intake

Congener-specific analyses of 7 polychlorinated dibenzo-p-dioxins (PCDDs), 10 polychlorinated dibenzofurans (PCDFs) and 4 non-ortho (coplanar) polychlorinated biphenyls (cPCBs) were performed on 197 foodstuffs samples of animal origin from Belgium during years 2000 and 2001. All investigated matrices (except horse) present background levels lower than the Belgian non-commercialization value of 5 pg TEQ/g fat. Pork was the meat containing the lowest concentration of both PCDD/Fs and cPCBs. The mean background concentration of 2,3,7,8-TCDD toxicity equivalent in milk was 1.1 pg/g of fat, with a congener distribution typical of non-contaminated milk. The relative contribution of 2,3,7,8-TCDD, 2,3,7,8-TCDF, 1,2,3,7,8-PeCDD and 2,3,4,7,8-PeCDF to the PCDD/Fs TEQ was 85+/-7.9% for all investigated matrices. The cPCBs contribution to the total TEQ was 47+/-19.0% for products of terrestrial species and 69+/-20.0% for aquatic species. Once the contribution of cPCBs was added to the TEQ, few foodstuffs such as horse, sheep, beef, eggs and cheese presented levels above the future European guidelines that currently only include PCDD/Fs but will be re-evaluated later in order to include 'dioxin-like' PCBs. Based on levels measured in the samples, the estimation of the dietary intake was 65.3 pg WHO-TEQ/day for PCDD/Fs only (1.00 pg WHO-TEQ/kg bw/day, for a 65 kg person) and 132.9 pg WHO-TEQ/day if cPCBs were included (2.04 pg WHO-TEQ/kg bw/day, for a 65 kg person). Meat (mainly beef), dairy products, and fish each account for roughly one third of the intake.     

Dioxin and dibenzofuran concentrations in blood of a general population from Tarragona, Spain

The concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were determined in plasma samples of 20 nonoccupationally exposed subjects living in the vicinity of a new hazardous waste incinerator (HWI), now under construction in Tarragona (Catalonia, Spain). The mean PCDD/F value was 27.0 pg I-TEQ/g lipid with a range from 14.8 to 48.9 pg I-TEQ/g lipid. All samples showed higher PCDD than PCDF levels. Although PCDD/F concentrations were higher in women (27.7 pg I-TEQ/g lipid) than in men (25.2 pg I-TEQ/g lipid), the difference was not statistically significant. While a significant correlation (r = 0.565, p < 0.01) between the age of the subjects and the levels of PCDD/F in plasma could be observed, no significant differences were found in relation to the specific residential area. The plasma concentrations of PCDD/F obtained in the current study are discussed and compared with the results of similar investigations reported in the last two years.     

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.     

A comparison of PCDD/PCDFs exposure in infants via formula milk or breast milk feeding

Food is the major source for polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) accumulation in human body. In infant period, breast milk and formula milk are the major food sources. Congener-specific analyses of 17 PCDD/PCDFs were performed on 10 brands of formula milk samples which were milk-based and 37 breast milk samples collected from women living in southern Taiwan. The levels of 17 PCDD/PCDFs in 10 formula milk samples ranged from 0.468 to 0.962 pg WHO-TEQ/g lipid, with a mean value of 0.713+/-0.163 pg WHO-TEQ/g lipid. For the 37 breast milk samples, their PCDD/PCDF levels were 14.7+/-9.36 pg WHO-TEQ/g lipid, with a range between 4.21 and 52.8 pg WHO-TEQ/g lipid. At 12th month of age for infants, average daily intakes (ADI) of PCDD/PCDFs were 2.1 pg WHO-TEQ/kg/day for the formula-feeding infants, and 13 pg WHO-TEQ/kg/day for the breast-feeding infants. The present data may provide useful information for risk-benefit evaluation of formula- and breast-feeding.     

Human PCDD/PCDF levels near a pentachlorophenol contamination site in Tainan, Taiwan

A pentachlorophenol (PCP) manufacturing plant in southern Taiwan discontinued production in 1989. The site of the abandoned plant was heavily contaminated by PCDD/PCDFs, impurities formed in the PCP production process. Serum samples collected from 27 residents living near the deserted plant were evaluated to determine whether this contamination had associated serum levels of PCDD/PCDFs in local residents. The average level of 17 tested congeners ranged from 556 to 5240 pg/g lipid (mean, 1670 pg/g lipid). The corresponding 2,3,7,8-TCDD toxicity equivalent quotient values calculated by international toxicity equivalent factors (I-TEFs) and those recommended by WHO (WHO-TEFs) were 47.2 pg I-TEQ/g lipid and 53.4 pg WHO-TEQ/g lipid, respectively. Levels in other parts of Taiwan typically range from 15 to 20 pg WHO-TEQ/g lipid; therefore, it is likely that the heavily contaminated plant site caused these unusually high serum levels. The average PCDD/PCDF levels of 29 fish-tissue and nine soil samples collected from the sea reservoir surrounding the abandoned PCP plant were also abnormally high: 8630 pg/g lipid (985 pg WHO-TEQ/g lipid) and 606000 pg/g-sample (922 pg WHO-TEQ/g-sample), respectively. Factor analysis indicated that the congener pattern of human serum samples collected from residents living near the abandoned PCP plant different from samples collected from other areas in Taiwan without known PCDD/PCDF pollution. Similar results were observed for the fish tissue and soil samples. The current study may have discovered a "hot spot" for elevated dioxin human exposure in Taiwan. The preliminary finding has raised a public health concern in the inspected area and requires further investigations to clarify the nature of the contamination and potential impact on the local environment and human health.