Polychlorinated biphenyls and organochlorine pesticides in milk and blood of Canadian women during lactation

Blood and breast milk samples of 16 women were analyzed for PCBs (polychlorinated biphenyls) and some organochlorine pesticides during eight intervals of a 98 day lactation period. Although a general downward trend in residue levels of blood and breast milk was evident, this trend was interrupted by sporadic increases. Most residues in breast milk showed an apparent increase during the first 30 days of lactation, which was not statistically significant. However, during lactation a statistically significant decrease was observed for the following residues, expressed on a milkfat basis: HCB (hexachlorobenzene), oxychlordane, transnonachlor (1-exo, 2-endo, 3-exo-4,5,6,7,8,8-nonachloro-3a,4,7,7a-tetrahydro-4,7-methanoindene), HCH (hexachlorocyclohexane),p,p-DDE andp,p-DDT. Average milk/blood ratios for PCBs, HCB, oxychlordane(1-exo,2-endo-4,5,6,7,8,8-oc-tachloro-2,3-exo-epoxy 2,3,3a,4,7,7a-hexa-hydro-4,7-methanoindene),p,p-DDE (2,2-bis-(p-chlorophenyl)- 1, 1-dichloroethylene), dieldrin (1,2,3,4, 10,10-hexachloro-exo-6,7-epoxy-1,4,4a,5,6,7,8,8a-octahydro- 1,4-endo- exo- 5,8-dimethanonaphthalene) and p,p-DDT (1,l-bis-(p-chlorophenyl)-2,2,2-trichloroethane) levels were 23, 20, 9, 19, 5 and 30 respectively. Milk/blood ratios for PCB andp,p-DDE levels remained relatively constant during lactation (coefficient of variation 20). Accumulation of residues in infant body fat were theoretically estimated     

Seasonal and geographical variation of organochlorine residues in birds from Northwest Mexico

Eight species of birds (129 individuals) were collected from three agricultural areas with long histories of pesticide use in northwestern Mexico. Plucked carcasses were analyzed for organochlorine (OC) pesticides and polychlorobiphenyls (PCBs). DDE was found in all of the samples and at higher levels than other OCs. Mean (geometric) DDE concentrations varied from 0.04 (g/g) ppm in mourning doves (Zenaida macroura) to 5.05 ppm in double-crested cormorants (Phalacrocorax auritus). Hexachlorocyclohexane (HCH) was detected in 95% of the samples, but at lower levels than DDE. Hexachlorobenzene (HCB) residues were detected more frequently in birds from Mexicali (62%, p < 0.05) than in those from Yaqui and Culiacan. HCH and HCB concentrations were significantly higher in birds from Mexicali during the winter than in the summer (p < 0.05), indicating accumulation of these compounds during that period. Other OCs such as DDT, DDD, dieldrin, oxychlordane, heptachlor epoxide, endosulfan, and endrin were found at lower levels and less frequently. PCBs (quantitated as Aroclor^® 1260) were found mostly in cattle egrets (Bubulcus ibis) and cormorants at the three locations. Overall, concentrations of OCs were higher for Mexicali than for Yaqui and Culiacan (p < 0.01). In a few cases, DDE levels were above those that might adversely affect birds.     

Characteristic trend of persistent organochlorine contamination in wildlife from a tropical agricultural watershed,South India

The residue levels of persistent organochlorines, such as HCH (BHC: 1,2,3,4,5,6-hexachlorocyclohexane) isomers, DDT [1,1,1-trichloro-2,2-bis (p-chlorophenyl) ethane] compounds, PCBs (polychlorobiphenyls) and HCB (hexachlorobenzene), were measured in wildlife. The wildlife were sampled from terrestrial and aquatic habitats in and around the agricultural watershed of Parangipettai, South India. On the basis of overall concentrations HCH ranked first followed by DDT, PCB and HCB, reflecting the increasing usage of HCH in recent years in India. The residue levels of organochlorines in birds varied according to their feeding habits and showed the following pattern: inland piscivores and scavengers > coastal piscivores > insectivores > omnivores > granivores. High levels of HCH and DDT residues were recorded in Pond heron and Cattle egret which feed in the agricultural fields. Comparison of HCH concentrations in fish and birds in the study area to other locations was made to further understand the dynamics of contaminant accumulation in tropical wildlife. Regarding birds, a wide variation in residue levels could be seen among various countries, with tropical regions registering high levels. In contrast, the variation is not prominent in the case of fish. The residue levels in fish measured in the present study were generally comparable to values reported from other locations. This suggests that the bioavailability of contaminants to the aquatic fauna is less due to the smaller flux and shorter residence time of these chemicals in the tropics.     

Effect of temperature and sunlight exposure on the fate of soil-applied [14C]-gamma-hexachlorocyclohexane

The role of temperature and solar radiation in the rapid dissipation of-1,2,3,4,5,6-hexachlorocyclohexane (-HCH) from Indian soils was determined by quantifying volatilization, mineralization, binding and degradation of [¹⁴C]-HCH in a sandy loam soil. An increase in temperature from 15 to 45°C caused a 6-fold rise in volatilization. Degradation as well as mineralization of HCH increased with temperature, although both were minimal. Bound residues of HCH in soil increased from 3.3% at 15°C to 16.7% at 45°C, after 28 days. In flooded soils, volatile losses nearly doubled, while binding and mineralization decreased. Exposure of HCH-treated soil to sunlight in quartz tubes showed a two-fold increase in volatilization over the dark controls. Formation of-2,3,4,5,6-pentachlorocyclohex-l-ene (-PCCH) in the unflooded soils and-3,4,5,6-tetrachlorocyclohex-1-ene (-TCCH) in the flooded systems were enhanced by sunlight. Trace amounts of-HCH were detected in the volatilized organics from the quartz tubes. Flooding the soil markedly increased volatile losses, thus leaving only 14% of the initial HCH as residues in soil after 42 days of exposure in quartz tubes. Neither flooding nor sunlight had any significant effect on HCH binding in soil. Mineralization, though amounting to a maximum of only 3% in the unflooded soil, was further reduced in submerged soils. The data demonstrate the significant influence of temperature, humidity and solar radiation, on the rapid loss of HCH from Indian subtropical soils, evidently by rapid volatilization.     

Residues of some organochlorine insecticides from some water bodies,their toxicity to mosquito larvae Culex pipiens pipiens and influence on mitochondrial ATPase of Bolti fish Tilapia niloticus

Residues of organochlorine insecticides were extracted from several water bodies, including irrigation canal, main drain, collector drains, brackish water of Bitter lake, and tap water around Ismailia, Egypt. Hexachloro cyclohexane (HCH) isomers were the most prevailing compounds detected. Highest residue concentration was detected in collector drains. Residues have shown an inductive effect on mitochondrial ATPase extracted from gills, liver and brain of Bolti fish Tilapia niloticus. Ouabrain, the potent Na‐K‐ATPase inhibitor has cancelled out the inductive effect residues inflected on gills and brain ATPase. The toxicity of the different organochlorine extracts to 3 ^rd instar larvae of Culex pipiens pipiens varied according to the source of residue.     

Residues of Hexachlorocyclohexane Isomers and Their Distribution Characteristics in Soils in the Tianjin Area, China

Hexachlorocyclohexane (HCH) has a history of use in China. This paper presents the results of an investigation of HCH residue isomers and their distribution characteristics in soils near Tianjin, China. One hundred eighty-eight soil samples were collected from the Tianjin area. Four HCH isomers—-HCH, -HCH, -HCH, and -HCH—were detected using gas chromatography for all samples. Concentrations of the HCH ranged from 1.3 to 1095 ng g^–1, among which -HCH accounted for 52.5%. In addition, residues of HCH within Tianjins urban areas were found to be higher. No significant differences were found between the residues of HCH in soils from waste irrigation areas and those in other areas. Total organic carbon content was determined to impact the residue levels of HCH in soils, while pH value and clay content were not related to concentrations of HCH. In general, all HCH isomers in soil samples had abnormally high residue levels, possibly the result of continuous use of HCH in this area.     

Temporal Trends of Organochlorine Pesticides in Prawn (<Emphasis Type="Italic">Macrobrachium nipponense</Emphasis>) from Lake Kasumigaura,Japan, During 1978–2000

Temporal trends of organochlorine pesticides such as -hexachlorocyclohexane (-HCH), hexachlorobenzene (HCB), and 1,1-dichloro-2,2-bis(p-chlorophenyl)-ethylene (p,p-DDE), were determined in freshwater prawn (Macrobrachium nipponense) collected from Lake Kasumigaura in 1978 to 2000. The organochlorine pesticides elucidated a 72.4% decrease in -HCH, from 42 (1978) to 11.6 ng/g fat (2000); an 89.6% decrease in HCB, from 1.64 (1978) to 0.17 ng/g fat (2000); and an 87.3% decrease in p,p-DDE, from 97.5 (1978) to 12.4 ng/g fat (1992). After organochlorine pesticide prohibition in 1971, the declining trend of -HCH, HCB, and p,p-DDE concentrations persisting in the prawns could be approximated by exponential equations.     

Organochlorine pesticides and polychlorinated biphenyls in maternal adipose tissue,blood, milk,and cord blood from mothers and their infants living in Norway

Samples of maternal blood, milk, and umbilical cord blood were collected from mothers and their infants at Ullevål University Hospital in Oslo, Norway. All the mothers had lived in Oslo during the last two years. Of the Norwegian mothers, 16 were delivered by Caesarean operation, and samples of subcutaneous fat tissues were collected. Hexachlorobenzene (HCB), polychlorinated biphenyls (PCBs),p,p-DDE,p,p-DDT, and dieldrin were found in 157, 135, 168, 22, and 12, respectively, of the 168 samples analyzed, while , and -hexachlorocyclohexane (HCH) were found in 93 and 26, respectively, of the 152 samples analyzed for these compounds. In the samples obtained from the Norwegian mothers and infants, PCBs andp,p-DDE were the major contaminants present. In contrast, only traces of PCBs were found in six immigrant samples, which, however, contained 4–6 times higher levels ofp,p-DDE plusp,p-DDT than the corresponding Norwegian samples. Of the HCH isomers, the -HCH was the predominant isomer present. Two to three times significantly higherp,p-DDE and PCBs levels were found in maternal serum than cord serum. No significant differences were found between the organochlorine residue levels in subcutaneous fat and milk fat. A significant positive linear correlation was found between the levels ofp,p-DDE and PCBs in maternal serum and in milk fat, and between the levels ofp,p-DDE in maternal serum and cord serum from Norwegian mothers giving birth normally.Significantly higher PCBs andp,p-DDE residues were found in the maternal and cord serum samples obtained after Caesarean operation than after normal delivery, while no other such differences were found in the milk samples 5 days post partum.The results demonstrate that organochlorines are transferred from mother to fetus and newborn babies through the placenta and milk and that human milk is a good indicator in monitoring human beings and their environment for organochlorine contamination. Possible toxicological implications of the present results are discussed.     

有机氯农药多残留GC-MS分析方法研究

应用Ｍａｓｌａｂ的定量软件，以选择离子扫描方式，建立了有机氯农药多残留的ＧＣ－ＭＳ定量测定方法。经方法的线性试验、精密度试验、检测限试验，验证了有机氯农药多残留ＧＣ－ＭＳ分析方法的可行性。ＰＣＮＢ和ｐｐ＇－ＤＤＴ在０．００２５～０．５０ｎｇ，α－ＨＣＨ、β－ＨＣＨ、γ－ＨＣＨ、δ－ＨＣＨ、ｏｐ＇－ＤＤＴ、ｐｐ＇－ＤＤＤ、ｐｐ＇－ＤＤＥ、ＨＣＢ在０．００２０～０．４０ｎｇ范围内呈现良好的线性关系；方法的最低检出量：ＰＣＮＢ和ｐｐ＇－ＤＤＴ为０．００２５ｎｇ，α－ＨＣＨ、β－ＨＣＨ、γ－ＨＣＨ、δ－ＨＣＨ、ｏｐ＇－ＤＤＴ、ｐｐ＇－ＤＤＤ、ｐｐ＇－ＤＤＥ、ＨＣＢ为０．００２０ｎｇ．精密度试验的变异系数满足了农药多残留痕量分析的要     

Organochlorine pesticides in commercial marine fishes of Coimbatore, India and their suitability for human consumption

Organochlorine pesticide residues were determined in 10 species of fishes caught at Cochin and Rameshwaram coast, and sold in Coimbatore, Tamil Nadu, India. Species were selected on the basis of their regular availability throughout the year and commercial value. A total of 389 fishes were analyzed for organochlorine residues and their suitability for human consumption was evaluated. Results show varying levels of residues of hexachlorocyclohexane (HCH), DDT, heptachlor epoxide, endosulfan and dieldrin. Among the 10 species, high concentration of pesticide residues were recorded in Sardinella longiceps, Carangoides malabaricus, Chlorophthalmus agassizi, Saurida tumbil and Rastrelliger kanagurta. The variation in total organochlorine residues among species and between places was not significant (P>0.05). Only five species of fishes showed monthly variation in residue levels and there was no significant correlation between the body size and residue levels in the tissue. About 22% of the fishes exceeded the maximum residue limits (MRL) of total HCH prescribed by FAO/WHO for fish products. The calculated dietary intake of total HCH through consumption of C. malabaricus, C. agassizi and S. longiceps exceeded the maximum acceptable dietary intake (ADI) limits prescribed for human consumption. The present study recommends continuous monitoring of environmental contaminants in marine fishes to assess the possible impact on human health.     

Organochlorine levels in North Atlantic right whale (Eubalaena glacialis) blubber

Polychlorinated biphenyls (PCBs), total DDT (DDT+DDE+DDD), dieldrin, heptachlor epoxide, chlordanes, and hexachlorobenzene (HCB) were found in blubber biopsies from endangered North Atlantic right whales (Eubalaena glacialis) in the Bay of Fundy and on Browns-Baccaro Banks. Analyses included four sex and age class composite samples from 1988, and 21 individual samples from 1989. Generally, PCBs demonstrated the highest wet weight residue levels (up to 1.9 g/g), followed by total DDT (DDT+DDE+DDD) (trace to 0.47 g/g). Relatively low residue levels in adult females suggest that transmammary organochlorine (OC) residue transfer occurs during lactation. The actual blubber residue loads may have been under-estimated, because the samples were taken when the whales were depositing fat reserves and the samples may not have been representative of the remainder of the blubber.     

Prepubertal Serum Concentrations of Organochlorine Pesticides and Age at Sexual Maturity in Russian Boys

Background

Few human studies have evaluated the impact of childhood exposure to organochlorine pesticides (OCP) on pubertal development.

Objective

We evaluated associations of serum OCP concentrations [hexachlorobenzene (HCB), β-hexachlorocyclohexane (βHCH), and p,p-dichlorodiphenyldichloroethylene (p,p´-DDE)] with age at attainment of sexual maturity among boys.

Methods

From 2003 through 2005, 350 8- to 9-year-old boys from Chapaevsk, Russia, with measured OCPs were enrolled and followed annually for 8 years. We used multivariable interval-censored models to evaluate associations of OCPs (quartiles) with three physician-assessed measures of sexual maturity: Tanner stage 5 for genitalia growth, Tanner stage 5 for pubic hair growth, or testicular volume (TV) ≥ 20 mL in either testis.

Results

In adjusted models, boys with higher HCB concentrations achieved sexual maturity reflected by TV ≥ 20 mL a mean of 3.1 months (95% CI: –1.7, 7.8), 5.3 months (95% CI: 0.6, 10.1), and 5.0 months (95% CI: 0.2, 9.8) later for quartiles Q2, Q3, and Q4, respectively, compared with Q1 (p trend = 0.04). Tanner stage 5 for genitalia growth was attained a mean of 2.2 months (95% CI: –3.1, 7.5), 5.7 months (95% CI: 0.4, 11.0), and 3.7 months (95% CI: –1.7, 9.1) later for quartiles Q2, Q3, and Q4, respectively, of βHCH compared with Q1 (p trend = 0.09). Tanner stage 5 for pubic hair growth occurred 6–9 months later on average for boys in the highest versus lowest quartile for HCB (p trend < 0.001), βHCH (trend p = 0.01), and p,p´-DDE (p trend = 0.04). No associations were observed between p,p´-DDE and Tanner stage 5 for genitalia growth or TV ≥ 20 mL.

Conclusions and relevance

Higher prepubertal serum HCB and βHCH concentrations were associated with a later age at attainment of sexual maturity. Only the highest quartile of serum p,p´-DDE was associated with later pubic hair maturation.

Citation

Lam T, Williams PL, Lee MM, Korrick SA, Birnbaum LS, Burns JS, Sergeyev O, Revich B, Altshul LM, Patterson DG Jr, Hauser R. 2015. Prepubertal serum concentrations of organochlorine pesticides and age at sexual maturity in Russian boys. Environ Health Perspect 123:1216–1221; http://dx.doi.org/10.1289/ehp.1409022     

Organochlorine pesticide contaminations in human milk samples from women living in Amman,Jordan

Concentrations of 15 organochlorine pesticides were determined by capillary gas chromatography in 59 human milk samples collected from the general population during 1989/1990 in the Jordanian capital of Amman. In addition to hexachlorbenzene (HCB), three groups of organochlorine compounds namely, DDT and its metabolites, hexachlorcyclohexane (HCH-isomers) and the cyclopentadiene group (aldrin, dieldrin, endrin, heptachlor, and heptachlor epoxide) were analyzed.The results show that almost all samples contained HCB, -HCH, p,p-DDE and p,p-DDT, whereas p,p-DDD, heptachlor, -HCH, -HCH and o,pDDT were found in 42, 40, 33, 22 and 20 analyzed samples, respectively. The concentration of HCB, -HCH, p,p-DDE, p,p-DDT and heptachlor expressed on a milk-fat basis (median in mg/kg milk fat): 0.29, 0.4, 2.04, and 0.7 respectively.For the comparative purposes and in order to try to find the possible sources of mother-milk contaminations, different types of locally produced and imported cow milk samples were also analyzed for the same organochlorine compounds. Almost all types of tested milk were contaminated with p,p-DDE.     

Exposure to Endocrine-Disrupting Chemicals during Pregnancy and Weight at 7 Years of Age: A Multi-pollutant Approach

Background

Prenatal exposure to endocrine-disrupting chemicals (EDCs) may induce weight gain and obesity in children, but the obesogenic effects of mixtures have not been studied.

Objective

We evaluated the associations between pre- and perinatal biomarker concentrations of 27 EDCs and child weight status at 7 years of age.

Methods

In pregnant women enrolled in a Spanish birth cohort study between 2004 and 2006, we measured the concentrations of 10 phthalate metabolites, bisphenol A, cadmium, arsenic, and lead in two maternal pregnancy urine samples; 6 organochlorine compounds in maternal pregnancy serum; mercury in cord blood; and 6 polybrominated diphenyl ether congeners in colostrum. Among 470 children at 7 years, body mass index (BMI) z-scores were calculated, and overweight was defined as BMI > 85th percentile. We estimated associations with EDCs in single-pollutant models and applied principal-component analysis (PCA) on the 27 pollutant concentrations.

Results

In single-pollutant models, HCB (hexachlorobenzene), βHCH (β-hexachlorocyclohexane), and polychlorinated biphenyl (PCB) congeners 138 and 180 were associated with increased child BMI z-scores; and HCB, βHCH, PCB-138, and DDE (dichlorodiphenyldichloroethylene) with overweight risk. PCA generated four factors that accounted for 43.4% of the total variance. The organochlorine factor was positively associated with BMI z-scores and with overweight (adjusted RR, tertile 3 vs. 1: 2.59; 95% CI: 1.19, 5.63), and these associations were robust to adjustment for other EDCs. Exposure in the second tertile of the phthalate factor was inversely associated with overweight.

Conclusions

Prenatal exposure to organochlorines was positively associated with overweight at age 7 years in our study population. Other EDCs exposures did not confound this association.

Citation

Agay-Shay K, Martinez D, Valvi D, Garcia-Esteban R, Basagaña X, Robinson O, Casas M, Sunyer J, Vrijheid M. 2015. Exposure to endocrine-disrupting chemicals during pregnancy and weight at 7 years of age: a multi-pollutant approach. Environ Health Perspect 123:1030–1037; http://dx.doi.org/10.1289/ehp.1409049     

National contaminant biomonitoring program: Residues of organochlorine chemicals in U.S. Freshwater Fish, 1976–1984

The U.S. Fish and Wildlife Service periodically determines concentrations of organochlorine chemicals in freshwater fish collected from a nationwide network of stations as part of the National Contaminant Biomonitoring Program (NCBP, formerly a part of the National Pesticide Monitoring Program). From late 1984 to early 1985, a total of 321 composite fish samples were collected from 112 stations and analyzed for organochlorine chemical residues. The mean concentrations of total DDT did not change from 1980–81 to 1984, following a period of steady decline through the 1970's; however, the mean concentrations ofp,p-DDT declined significantly. The most persistent DDT homolog (p,p-DDE) was detected at 98% of the stations sampled in 1984, and constituted 73% of total DDT residues, up from 70% in 1974–79. Collectively, these findings indicate a low rate of influx and continued weathering of DDT in the environment. Residues of polychlorinated biphenyls (PCBs) also remained widespread, but a significant downward trend in total PCBs was evident, and early eluting PCB components were present at fewer stations than in the past. Mean concentrations of dieldrin have not changed since 1978–79; concentrations remained highest in Hawaii and in the Great Lakes. Toxaphene concentrations declined from 1980–81 to 1984, especially in the Great Lakes, and the incidence of toxaphene declined from 88% of the stations sampled in 1980–81 to 69% in 1984. Mean chordane concentrations did not change from 1980–81 to 1984, following a period of decline; however,trans-nonachlor replacedcis-chlordane as the most abundant component, suggesting a lower influx of chlordane to the aquatic environment. Residues of other organochlorines—mirex, pentachloroanisole (PCA), benzene hexachloride (BHC) isomers, endrin, heptachlor, hexachlorobenzene (HCB), and Dacthal^® (DCPA)—were either found at relatively few (<25%) of the stations sampled in 1984 or were characterized by relatively low concentrations. In general, organochlorine concentrations were lower in 1984 than at any time reported previously.     

Contamination by Selected Organochlorine Pesticides (OCPs) in Surface Soils in Hanoi, Vietnam

An evaluation of selected organochlorine pesticide residues [p,p′- dichlorodiphenyltrichloroethane (DDT), p,p′- dichlorodiphenyldichloroethylene (DDE), p,p′- dichlorodiphenyldichloroethane (DDD), α, β, γ and δ- hexachlorocyclohexane (HCH)] in the surface soils of Hanoi, Vietnam was carried out. Sixty representative soil samples were collected from the centre of Hanoi and five surrounding districts. In agricultural areas, ΣDDT concentrations ranged from < 0.02 to 171.83 ng g⁻¹ (mean 89.86 ng g⁻¹) dry weight, whereas ΣHCH concentrations ranged from < 0.05 to 20.57 ng g⁻¹ (mean 8.03 ng g⁻¹) dry weight. Investigation of the ratio of different isomers in the soil samples indicates that there has been no recent input of DDT and HCH in the study area.     

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

Summary A cytogenetic study was performed on 20 healthy workers exposed to pentachlorophenol (PCP) in concentrations ranging from 1.2 to 180 g/m³ (Maximum Concentration at the workplace is 500 g/m³) for 3 to 34 years. PCP was determined in the blood plasma of all probands, yielding concentrations between 23 and 775 g/l (Biological Tolerance Value is 1000 g/1). In vitro PCP up to 90 mg/l was added to phytohaemagglutinin stimulated lymphocytes of normal healthy donors without any effect on sister chromatid exchange (SCE) or chromosomal aberrations (CA), whereas a slowdown of cell proliferation could be detected in the presence of 60 mg PCP/l. In vivo we neither observed a relation between PCP concentrations and the number of SCE nor an increase of CA.     

National Pesticide Monitoring Program: Residues of organochlorine chemicals in freshwater fish, 1980–81

The U.S. Fish and Wildlife Service analyzed residues of organochlorine chemicals in 315 composite samples of whole fish collected in 1980–81 from 107 stations nationwide as part of the National Pesticide Monitoring Program (NPMP). The mean concentrations of total DDT and allp,p-ho-mologs exceptp,p-DDT showed significant but small declines relative to mean concentrations before 1978–79. The mean concentration ofp,p-DDT did not change. The most persistent DDT homolog (p,p-DDE) continued to constitute about 70% of total DDT residues, as it did in 1974–79. DDT contamination attributable to former DDT manufacturing facilities remained evident at sites in Alabama and Arkansas, and high concentrations at one site in Hawaii suggested that input to the environment was continuing. Conversely, the data do not support the contention of others that DDT was still being used in the Southwest. Residues of polychlorinated biphenyls (PCBs) remained widespread, but a significant downward trend in total PCBs was evident, especially in areas that the NPMP has previously shown to be the most heavily contaminated. Mean concentrations of dieldrin had not changed since 1978–79, and levels remained highest in Hawaii and in the Great Lakes. Toxaphene concentrations plateaued after a period of steady increase through the 1970's, but the incidence of toxaphene continued to increase; residues were present at 88% of the stations sampled in 1980–81, including one in Alaska (most likely as a consequence of atmospheric transport). Mean chlordane concentrations were slightly lower than in 1978–79, and residues were detected at fewer stations in 1980–81 than in 1978–79. Residues of other organochlorines [e.g., mirex, pentachloroanisole (PCA), benzene hexachloride (BHC) isomers, endrin, heptachlor, hexachlorobenzene (HCB), Dacthal^® (DCPA)², and methoxychlor] were either found at relatively few (<25%) of the stations sampled in 1980–81 or were characterized by relatively low concentrations.     

Toxicological assessment of biodegraded pentachlorophenol: Microtox® and fish embryos

A Gram-negative bacterium,Pseudomonas sp. strain SR3, was isolated from soil at a former wood treatment plant in north central Florida. The ability of this bacterium to degrade pentachlorophenol (PCP) was confirmed by growing cells in a basal salts medium in which PCP was the only source of carbon and energy. Degradation from a measured concentration of 39–40 g PCP/ml to 0.0006 g PCP/ml was observed within 120 h of incubation in the presence of PCP-induced cells ofPseudomonas sp. strain SR3. The initial cell density in these cultures was 6 x 10⁶ cfu/ml. Microtox^® 5 min EC50 toxicity tests revealed that aqueous solutions of PCP, measured concentrations 39–40 p /ml were toxic but that final biodegraded samples, 0.0006 /g PCP/ml were nontoxic. However, bioassays with embryonic inland silversides,Menidia beryllina, showed that the biodegraded samples were embryotoxic or teratogenic. Water containing added PCP at concentrations up to 30 times higher than measured in the final biodegraded samples was less toxic/teratogenic. These results indicate that while biodegradation of PCP was nearly complete, intermediate metabolites of the degradation process or undegraded impurities in PCP were toxic or teratogenic. Thus, theM. beryllina bioassay allows extremely sensitive assessment of toxicity associated with biodegraded environmental pollutants and may be a useful criterion for determining whether bioremediated water or soil is safe for discharge back into the environment.Contribution No. 777 of the Gulf Breeze Environmental Research Laboratory.     

Serum organochlorines and urinary porphyrin pattern in a population highly exposed to hexachlorobenzene

Background

Porphyria cutanea tarda (PCT) is caused by hexachlorobenzene (HCB) in several species of laboratory mammals, but the human evidence is contradictory. In a study among adults of a population highly exposed to HCB (Flix, Catalonia, Spain), the prevalence of PCT was not increased. We aimed at analysing the association of individual urinary porphyrins with the serum concentrations of HCB and other organochlorine compounds in this highly exposed population.

Methods

A cross-sectional study on total porphyrins was carried out in 1994 on 604 inhabitants of the general population of Flix, older than 14 years. Of them, 241 subjects (comprising a random sample and the subgroup with the highest exposure) were included for the present study. The porphyrin profile was determined by high-pressure liquid chromatography. Serum concentrations of HCB, as well as common organochlorine compounds, were determined by gas chromatography coupled to electron capture detection.

Results

Coproporphyrin I (CPI) and coproporphyrin III (CPIII) were the major porphyrins excreted, while uroporphyrins I and III were only detected in 2% and 36% of the subjects respectively, and heptaporphyrins I and III in 1% and 6%, respectively. CPI and CPIII decreased with increasing HCB concentrations (p < 0.05). This negative association was not explained by age, alcohol, smoking, or other organochlorine compounds. No association was found between uroporphyrin I and III excretion, nor heptaporphyrin excretion, and HCB. CPIII increased with smoking (p < 0.05).

Conclusion

HCB exposure in this highly exposed population did not increase urinary concentrations of individual porphyrins.