Organochlorine Pesticide Levels in Blood Serum Samples Taken at Autopsy from Auto Accident Victims in Veracruz,Mexico

Samples of human blood sera (N = 118) for the determination of organochlorine pesticide levels were obtained at autopsy from auto accident victims in Veracruz, Mexico, during the years 2000 and 2001. The presence of hexachlorobenzene (HCH), beta-hexachlorocyclohexane (β-HCH), 2,2-bis(p-chlorophenyl)-1,1-dichloroethylene (p,p[icaron]-DDE), 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (p,p[icaron]-DDT), and o,p[icaron]-DDT was confirmed by gas-liquid-electron-capture detection chromatography. During the years 2000 and 2001, the respective mean levels of (a) HCB, (b) β-HCH, (c) p,p[icaron]-DDE, (d) o,p[icaron]-DDT, (e) p,p[icaron]-DDT, and (f) total DDT were (a) 2.1 ng/ml and 1.4 ng/ml, (b) 3.0 ng/ml and 3.6 ng/ml, (c) 21.1 ng/ml and 23.8 ng/ml, (d) 1.2 ng/ml and 0.8 ng/ml, (e) 3.3 ng/ml and 2.5 ng/ml, and, finally, (f) 25.4 ng/ml and 27.1 ng/ml, respectively. High levels of persistent organochlorine pesticides were—and continue to be—present in the blood of individuals who live in Mexico. Levels of insecticide metabolites (e.g., β-HCH, p,p[icaron]-DDE) in blood have increased during recent years (1997–2001), but levels of p,p[icaron]-DDT decreased in 2001 because the use of DDT for the control of malaria in Mexico was restricted.     

Organochlorine Pesticide Level Differences Among Female Inhabitants from Veracruz,Puebla and Tabasco,Mexico

Organochlorine pesticides have been used in Mexico in malaria control programs and against ectoparasites. The objective of this study was to compare the levels of organochlorine pesticides: HCB, α-β-γ-HCH, pp′-DDE, op′-DDT and pp′-DDT in adipose tissue of female inhabitants from three Mexican states: Veracruz, Puebla and Tabasco. Data analyses indicated higher β-HCH levels in Puebla inhabitants. When comparing the mean values of the pp′-DDE concentrations among the three states, no statistically significant differences were noted. A trend of increasing concentrations of op′-DDT from Veracruz to Puebla and Tabasco was observed. Significantly higher pp′-DDT concentrations in Veracruz as compared to Puebla and Tabasco were determined. Using factorial analysis of three age categories (>30, 31–50, <51) organochlorine pesticide concentrations increases with age of participants, indicating time of exposure as a principal factor of organochlorine pesticides accumulation in adipose tissue.     

Organochlorine Pesticide Levels in Adipose Tissue of Pregnant Women in Veracruz, Mexico

DDT and Lindane (γ-HCH) which were used until 1999 in Mexico, have provided great benefits in the combat of vectors that spread infection-borne diseases and in agriculture for crop protection. The persistence in the environment and their accumulative properties results in bioconcentration in lipid rich tissues of the human body that reflect the extent of environmental pollution. Human adipose tissue samples were taken during 2009 from abdominal cavities of 69 pregnant women by cesarean surgery and from 34 samples of control donors by autopsy in Veracruz State. The samples were analyzed by gas chromatography with ECD. The results of mean levels (mg/kg on fat basis) were higher in controls compared to pregnant women β-HCH 0.064 vs 0.027; pp′DDE 1.187 vs. 0.745; op′DDT 0.016 vs. 0.011; pp′DDT 0.117 vs. 0.099 and Σ-DDT 1.337 vs. 0.854. The pregnant women group was divided according to age: up to 20, 20–30, and more than 30 years, and presented an increase for the more persistent pesticides with age in terms of mean concentrations and a more pronounced higher correlation in medians levels. Pairing Body Mass Index to organochlorine pesticide mean levels revealed no correlation between these factors in pregnant women.     

Organochlorine Pesticide Levels in Umbilical Cord Blood of Newborn in Veracruz, Mexico

Organochlorine pesticides accumulate in lipid rich compartments of organisms. During pregnancy, the compounds pass through the placental barrier appear in cord blood. The aim of this study was to monitor the levels of organochlorine pesticides in 70 umbilical cord blood samples taken during deliveries in Veracruz in 2009. For organochlorine pesticides, only the presence β-HCH (4%, 3.9 μg/L median concentration on wet weight), pp′DDE (100%, 0.7 μg/L) and pp′DDT (4%, 1.4 μg/L) were detected. The total pool of samples divided according to sex of new born babies, showed no statistical differences among median concentrations. The number of deliveries considered as a determinant contamination factor affirmed there were no statistical differences among median concentrations; however pp′DDE levels increased from the one to two childbirth groups. Age of pregnant women as a discriminate factor manifests in a significant increase in contamination levels among first, second and third tertile. In general, umbilical cord blood samples in Veracruz contained organochlorine pesticides, especially pp′DDE, confirming the presence of these compounds in the environment and their transfer from the mother to the developing fetus.     

Comparison of Organochlorine Pesticide Levels in Human Adipose Tissue of Inhabitants from Veracruz and Puebla, Mexico

Since the discovery of insecticide properties of DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane) and HCH (hexachlorocyclohexane), they have provided great benefits to humans in sanitary actions to combat the spread of infection-borne disease vectors. Public Health Programs in Mexico used DDT and HCH until 1999 as the insecticides of choice to control disease-transmitting organisms. Because of their persistence and accumulative properties, organochlorine pesticides bioconcentrate in lipids of the human body, reflecting the rate of environmental exposure. Eighty human abdominal adipose tissue samples from Veracruz and 80 samples from Puebla were analyzed and the obtained results were compared among both populations. The results from Veracruz showed higher contamination levels (mg/kg on lipid base) compared to Puebla: β-HCH, 0.072 vs. 0.029; pp′DDE (Dichlorodiphenyldichloroethylene), 2.364 vs. 0.726; op’DDT, 0.022 vs. 0.025; pp′DDT, 0.192 vs. 0.061; and Σ-DDT, 2.589 vs. 0.806. The population from Veracruz and from Puebla divided by sex, origin, and cause of death presented no statistical differences. The comparison between sexes (women and men groups) at Veracruz and Puebla indicated significantly higher levels in Veracruz and statistical significant differences. Calculating possible risks (odds ratios, OR), pp′DDE (OR = 5.04) and op′DDT (OR = 2.93) revealed significantly higher risk for the Veracruz population. The study indicated prolonged DDT exposure of Mexicans caused by the past sanitary use and persistence of its residues in soils and air.     

Monitoring of Organochlorine Pesticide Residue Levels in Adipose Tissue of Veracruz,Mexico Inhabitants

The concentrations of 20 Polychlorinated biphenyls (PCBs) were determined in 12 superficial sediments collected from The Ghar El Melh lagoon. Sediment samples were extracted by Soxhlet and analyzed by Gas chromatography with electron capture detector. The concentrations of PCBs, as sum of the 20 congeners, ranged from not detected to 3.987 ng/g on a dry weight basis, with a predominance of highly chlorinated (penta- and hepta-chlorobiphenyls) congeners. No significant correlation was found between the total PCB concentrations and organic carbon content suggesting that sediment organic carbon content did not play an important role in controlling the PCBs levels in the sediments. PCB levels in sediments were compared with Sediments Quality Guidelines (ERM–ERL indexes) for evaluation probable toxic effects on marine organism. The PCBs concentrations were lower than ERM and ERL values for all the collected samples.     

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.     

Assessment of persistent organic pollutants levels in blood samples from Quintana Roo,Mexico

The Stockholm Convention on persistent organic pollutants (POPs) sought to determine baseline exposures to POPs in the general population; however, in developing countries, exposure to these chemicals in hot spots may be an issue of public health considering its magnitude. Therefore, the aim of this study was to assess the levels of POPs in the blood of children living in three communities in the Southeastern Region of Mexico. During 2007, we studied a total of 96 healthy children (aged 6–12 years). Quantitative analyses were performed using gas chromatography coupled with mass spectrometry. High levels of p,p′-DDT and its principal metabolite, p,p′-DDE, were found in the blood of children living in the three communities studied, the levels ranged from 463.5 to 9046.3 ng/g lipid and from 490.8 to 57,712.4 ng/g lipid for DDT and DDE, respectively. In addition, high levels of lindane (γ-HCH) were found, with mean levels ranging between 575.4 and 6580.6 ng/g lipid. Moreover, children living in the study region were also exposed to polychlorinated biphenyls (PCBs), and the levels of these compounds in the blood of children were very similar between the communities with mean levels of around 3000 ng/g lipid (total PCBs). In conclusion, we demonstrated that children living in the studied communities were exposed to complex chemical mixtures (DDT, DDE, lindane and PCBs) rather than to individual compounds. Therefore, in future studies it is important to understand the potential interactions between the components of these mixtures.     

Organochlorine pesticide accumulation and genotoxicity in Mexican free-tailed bats from Oklahoma and New Mexico

The summer population of Mexican free-tailed bats (Tadarida brasiliensis) at Carlsbad Caverns, New Mexico, declined from an estimated 8.7 million in 1936 to 200,000 in 1974; thereafter, it increased to approximately 700,000 in 1991. This decline has been attributed primarily to organochlorine (OC) pesticide contamination and habitat disturbance. Similar declines have been observed in other populations of this species. This study examined the potential genotoxic effects of OC pesticide contamination on two populations of T. brasiliensis. Pesticide accumulation, frequencies of chromosomal aberrancy, and nuclear DNA content variation in spleen and testicular tissues were examined in specimens collected from Carlsbad Caverns and Vickery Cave, a maternity colony in northwestern Oklahoma, during the summers of 1990 and 1991. Pesticide residues in brain and carcass tissues were identified and quantified by electron capture gas chromatography. Genotoxicity was examined with the standard bone marrow chromosomal aberration assay and flow cytometry. Statistical relationships among pesticide content, observed chromosomal aberrancy, and nuclear DNA content variation were examined. Both populations demonstrated significant levels of DDE contamination; however, the Carlsbad Caverns population showed consistently higher pesticide loads. Males also demonstrated higher levels than females. No statistical differences in chromosomal aberrancy or nuclear DNA content variation were observed among sexes, sites, or collected periods. Positive correlations were detected between brain and carcass DDE concentrations for all bats examined. A significant negative relationship was found between brain DDE concentration and coefficients of variation in spleen DNA content only for males.     

Organochlorine Pesticide Levels in Maternal Adipose Tissue, Maternal Blood Serum, Umbilical Blood Serum, and Milk from Inhabitants of Veracruz, Mexico

Organochlorine pesticides, due to their persistence, accumulate in food chains and cause elevated contamination in human beings. These residues bioconcentrate in lipid-rich tissues according to the equilibrium pattern of internal transport and lipid tissue content. The analyses of maternal adipose tissue, maternal blood serum, umbilical blood serum, colostrum, and mature milk indicate circulation of these compounds through all compartments of the maternal body, including their crossover of the placental barrier. The greatest residue levels found correspond to DDTs, with highest levels determined in colostrum (5.71 mg/kg of DDT total), followed by adipose tissue with 5.66 mg/kg and in mature milk with 4.70 mg/kg. Among DDTs, pp'DDE is the most predominant compound. The paired analyses of organochlorine pesticide residue levels between mother blood serum and umbilical blood serum demonstrate significant correlation and their transfer from mother to fetus through the placenta. The paired analyses of adipose tissue and colostrum and mature milk contamination levels indicate a high degree of coherence, principally of DDT, in the body and lactation as a decontamination means. Received: 6 May 2000/Accepted: 12 September 2000     

Organochlorine pesticide residue levels in human milk: Western Australia, 1979-1980

Two hundred sixty-seven samples of breast milk, supplied by 140 donors from both urban (N = 45) and rural (N = 95) areas, were analyzed on a whole milk basis for aldrin, gamma-benzene hexachloride (gamma BHC), hexachlorobenzene (HCB), dieldrin, and total dichlorodiphenyltrichloroethane (DDT) to ascertain the effectiveness of restrictions placed on pesticide use since 1971. Aldrin and gamma BHC were found to be present mainly in trace amounts, while decreases were found with HCB (0.025-0.008 ppm) and total DDT (0.078-0.046 ppm). Dieldrin showed an increase (0.005-0.009 ppm) which caused some concern. The results of a questionnaire suggested a connection between the high dieldrin levels and a program of treatment for the protection of houses against termites. A statistical analysis further supported this theory and suggested three variables being significantly associated with dieldrin levels: (1) treatment of the house, (2) suburb in which the donor lived, and (3) age of the mother. Further relationships were shown to exist between pesticide levels, lipid content of the milk, and the stage of feeding at which the sample was taken.     

Polybrominated diphenyl ethers (PBDEs) levels in blood samples from children living in the metropolitan area of Guadalajara,Jalisco, Mexico

The aim of this study was to perform a polybrominated diphenyl ethers (PBDEs) exposure assessment using blood samples collected from children living in the metropolitan area of Guadalajara, Jalisco, Mexico (GDL). Five congeners of PBDEs were analyzed using a gas chromatography/mass spectrometry technique. The blood concentrations of total PBDEs ranged from 5.50 to 169 ng/g lipid (42.0 ± 18.0 ng/g lipid; mean ± standard deviation). Regarding BDE congeners, the main congener (highest blood levels) was BDE99 (14.5 ± 5.50 ng/g lipid), followed by BDE100 (9.80 ± 3.40 ng/g lipid) and BDE154 (9.80 ± 5.90 ng/g lipid), and finally BDE153 (5.80 ± 2.30 ng/g lipid) and BDE47 (2.20 ± 1.20 ng/g lipid). In conclusion, blood PBDEs concentrations of concern were detected in this study, as blood levels were similar to the ones found in North America (the highest worldwide).