Levels of organochlorine pesticides in Beijing human milk, 1998

DDTs in mothers' milk, placenta and hair, and health risk assessment for infants at two coastal and inland cities in China

This study is a one of the very few investigating the dichloro-diphenyl-trichloroethanes (DDTs) (summation of o,p'-DDE, p,p'-DDE, o,p'-DDD, p,p'-DDD, o,p'-DDT, and p,p'-DDT) in multiple human matrices in mothers' milk, placenta and hair collected from residents from two coastal cities: Guiyu (GY) and Taizhou (TZ) and one inland city: Lin'an (LA). TZ (milk: 360±319ng/g lipid wt.) showed significantly higher concentrations of DDTs than those from LA (milk: 190±131ng/g lipid wt.), whereas, concentrations of DDTs in GY (milk: 305±109ng/g lipid wt.) were in between TZ and LA. In addition, levels of DDTs in the human tissues from TZ (placenta: 122±109ng/g lipid wt.; hair: 79.9±215ng/g dry wt.) were significantly higher than those from Lin'an (placenta: 49.2±30.2ng/g lipid wt.; hair: 10.8±7.09ng/g dry wt.). The above concentrations of DDTs in milk exceeded the Codex Maximum Residue Limits/Extraneous Maximum Residue Limits for milk (20ng/g lipid wt. whole milk), indicating that the human milk samples were grossly polluted. The present study revealed that human specimens collected from the coastal city (TZ) were more contaminated with inland one (LA), based on the levels of DDTs contained in samples which may be due to the higher dietary exposure to DDTs via consumption of contaminated seafood. The estimated daily intakes of DDTs by GY, TZ and LA infants were 1.69±1.86, 1.48±0.79, and 0.95±0.73μg/kg body wt./day, respectively which did not exceed 10μg/kg body wt./day, the provisional tolerable daily intake proposed by the Food and Agriculture Organization/World Health Organization.

Dietary exposure to DDTs in two coastal cities and an inland city in China

Dietary intakes of dichloro-diphenyl-trichloroethanes (DDTs) of residents from two coastal cities: Guiyu (GY) and Taizhou (TZ) and one inland city: Lin'an (HZ) were investigated by collecting 73 food items (divided into 9 food groups). The oriental weatherfish and white crab (both from TZ) contained higher DDTs (112±1.81 and 70.1±1.81 ng/g wet wt, respectively) than the maximum admissible concentration (50 ng/g wet wt) set by the European Union for human consumption. Furthermore, 40% of TZ seafood, 56% of GY and 30% of HZ freshwater fish exceeded the guideline for subsistence fish eaters for DDTs (14.4 ng/g wet wt) defined by the United States Environmental Protection Agency (US EPA). The estimated daily intakes of DDTs for TZ (52.1 ng/kg bw/day) and GZ (31.5 ng/kg bw/day) were significantly higher than for HZ (13.0 ng/g wet wt, p<0.05), these values were below the US EPA oral reference dose (500 ng/kg bw/day) and the Food and Agriculture Organization of the United Nations and the World Health Organization provisional tolerable daily intake (10,000 ng/kg bw/day).

Distributions, sources, and ecological risks of hexachlorocyclohexanes in the sediments from Haihe Plain, Northern China

The levels of hexachlorocyclohexanes (HCHs) in the sediments from Haihe Plain, China, were measured by a gas chromatograph with a (63)Ni microelectron capture detector. The spatial distributions, possible sources, and potential ecological risks of these compounds were analyzed. The residual level of total HCHs was 33.84 ± 173.37 ng g(-1) dry weight (d.w.) with ranges of 0.13 ~ 1,107.41 ng g(-1) d.w. Much higher ΣHCH contents were found in the lower reaches of some rivers and in the mouth of the main stream receiving tributaries. The predominance of β-HCH (36%) in the sediments was similar to that in the soils from Haihe Plain. The high percentages of γ-HCH (23-41%) could be detected at 25% of the sampling sites in the seven river systems. There were statistically significant positive relationships between the contents of HCHs and total organic carbon. Lindane was identified as the primary source of HCHs in the sediments, and it seemed that recent illegal lindane inputs still existed in some areas in Haihe Plain, as indicated by the α-/γ-HCH and β-/(α + γ)-HCH ratios. Severe potential ecological risks of γ-HCH to benthic organisms at some sampling sites were found based on the consensus-based sediment quality guidelines.

Distributions, sources, and ecological risks of DDT-related contaminants in water, suspended particulate matter, and sediments from Haihe Plain, Northern China

The residual levels of dichlorodiphenyltrichloroethane (DDT) and its metabolites (DDXs, including p,p'-DDT, DDD, and DDE) in water, suspended particulate matter (SPM), and sediments from major rivers, lakes, and reservoirs in Haihe Plain were measured with a gas chromatograph equipped with a (63)Ni microelectron capture detector. In the fall of 2004, the contents of the total DDXs in the water and SPM were 0.29 ± 0.69 ng L(-1) and 423.13 ± 577.85 ng g(-1) dry wt., respectively. In the spring of 2005, the total DDXs were 0.36 ± 0.91 ng L(-1) for water and 35.93 ± 62.65 ng g(-1) dry wt. for SPM. The average concentration of DDXs for sediments was 7.10 ± 7.57 ng g(-1) dry wt. during the two seasons. The Eastern-Hebei-Province Coastland River System was the most polluted, which was mainly attributable to the extensive use of DDT pesticide and dicofol in that system. Recent DDT inputs still occur in some regions, as indicated by DDT/(DDD + DDE) > 1 at 29-36 % of the sites for water and 55-61 % of the sites for SPM. The potential ecological risks of DDT in the water were assessed using a species sensitivity distribution model. Only shrimp and crabs were found to have potentially affected fraction values of 1.63 × 10(-3) to 2.27 × 10(-4), with probabilities beyond the hazardous concentration for 5 % of species (HC5) values of 1.90-2.56 %, suggesting only slight risks. DDXs in the sediments of some sites were also of potential risk to benthic organism based on consensus-based sediment quality guidelines.

Concentration of DDT compounds in breast milk from African women (Manhiça, Mozambique) at the early stages of domestic indoor spraying with this insecticide

Breast milk concentrations of 4,4'-DDT and its related compounds were studied in samples collected in 2002 and 2006 from two populations of mothers in Manhiça, Mozambique. The 2006 samples were obtained several months after implementation of indoor residual spraying (IRS) with DDT for malaria vector control in dwellings and those from 2002 were taken as reference prior to DDT use. A significant increase in 4,4'-DDT and its main metabolite, 4,4'-DDE, was observed between the 2002 (median values 2.4 and 0.9 ng/ml, respectively) and the 2006 samples (7.3 and 2.6 ng/ml, respectively, p<0.001 and 0.019, respectively). This observation identifies higher body burden intakes of these compounds in pregnant women already in these initial stages of the IRS program. The increase in both 4,4'-DDT and 4,4'-DDE suggest a rapid transformation of DDT into DDE after incorporation of the insecticide residues. The median baseline concentrations in breast milk in 2002 were low, and the median concentrations in 2006 (280 ng/g lipid) were still lower than in other world populations. However, the observed increases were not uniform and in some individuals high values (5100 ng/g lipid) were determined. Significant differences were found between the concentrations of DDT and related compounds in breast milk according to parity, with higher concentrations in primiparae than multiparae women. These differences overcome the age effect in DDT accumulation between the two groups and evidence that women transfer a significant proportion of their body burden of DDT and its metabolites to their infants.

Body burden of POPs of Hong Kong residents, based on human milk, maternal and cord serum

This study is one of the very few investigating the body burdens of persistent organic pollutants in residents of Hong Kong. Twenty-nine human milk samples and 21 human blood (and cord blood) samples collected from 2005 were analyzed for PAHs, OCPs and PCBs levels. Higher levels of PAHs, DDTs and PCBs were detected in human milk samples when compared to maternal serum and cord serum (PAHs: milk: 1981 ng g⁻¹ fat, maternal serum: 1461, cord serum: 1158; DDTs: 3099, 1934, 1556; PCBs: 49, 41, 40). Among the 16 PAHs, naphthalene (human milk: 786 ng g⁻¹ fat, maternal serum: 331, cord serum: 348), phenanthrene (361, 144, 193), pyrene (187, 154, 98) and fluoranthene (158, 128, 89) were the major PAHs detected in three human tissues. p,p'-DDE and p,p'-DDT were the only metabolites of DDT detected in the three types of human tissues. High detection rate of the p,p'-DDE and p,p'-DDT (> 90%) were noted in the three types of human samples. On the contrary, low detection frequency of PCBs in human milk (10.7%), maternal serum (1.7%) and cord serum (0.8%) were observed. The correlation coefficients of the PAHs, DDTs and PCBs levels in the three types of human tissues together with fish consumption, maternal age and tissue fat were analyzed. The following significant correlations were observed: Σ DDTs and p,p'-DDE in human milk with consumption of freshwater and marine fish, and maternal age; Σ PCBs in human milk with marine fish consumption, and maternal age; Σ PAHs in human milk with maternal age, respectively. The estimated daily intakes of DDTs by infants indicated that 7 out of 29 of the human milk samples exceeded 20 ng g⁻¹ day⁻¹, the tolerable daily intake (TDI) proposed by the Health Canada Guideline in terms of DDTs levels. The high intake of DDTs by infants may be of concern as infants are more susceptible to the adverse effects imposed by various environmental contaminants. Human milk is a reliable and comparatively non-invasive tool for monitoring body loading of POPs, which also allows health risk assessment of residual chemicals on our next generation.

Levels of persistent organic pollutants in human milk in two Chinese coastal cities, Tianjin and Yantai: Influence of fish consumption

In 2006-2007, we collected human milk from 60 and 48 donors in the Chinese coastal cities of Tianjin and Yantai, respectively, in accordance with the WHO/UNEP global milk survey. We determined the concentrations of organochlorine pesticides by GC/MS/MS and dioxins by XDS-CALUX bioassay in the individual milk specimens. The geometric mean concentrations (GMs) of beta-HCH (586.7ng g(-1) fat), total DDTs (855.9ngg(-1) fat), and dl-PCBs (4.4pg CALUX-TEQg(-1) fat) in the milk from Yantai were higher than those from Tianjin (254.4ng g(-1) fat, 654.7ngg(-1) fat, 1.9pg CALUX-TEQ g(-1) fat, respectively). However, the GMs of HCB (41.1ngg(-1) fat) and PCDD/Fs (13.1pg CALUX-TEQg(-1) fat) from Tianjin were higher than those from Yantai (15.7ng g(-1) fat, 9.9pg CALUX-TEQ g(-1) fat). The low ratios of DDT/(DDE+DDD) in milk from both areas suggested that past exposure contributed to the total DDTs body burden. The dl-PCBs body burden in the high sea fish intake group was higher than that in the low intake group, both with and without adjustments for potential influencing factors. For beta-HCH, a marginal P value (P=0.063) was observed between high and low sea fish consumption groups after adjusting for potential influencing factors. Donors in the high freshwater fish group showed higher PCDD/Fs and HCB levels than those in the low intake group, both with and without adjustments. Further monitoring studies of POPs contamination in human milk and foods are needed in China.

Seasonal patterns and current sources of DDTs, chlordanes, hexachlorobenzene, and endosulfan in the atmosphere of 37 Chinese cities

China has a history of large scale production and application of organochlorine pesticides (OCPs) although, data on their nationwide distribution and seasonal variations in the atmosphere is still sparse. Passive air samplers (PAS) were therefore utilized to obtain seasonal data from 37 Chinese cities and three background sites in 2005. Concentrations and spatial and seasonal distribution of dichlorodiphenyltrichloroethanes (DDTs), chlordanes (CHLs), hexachlorobenzene (HCB), and endosulfans (Endo) are presented in this paper, and their potential sources are discussed based on the dataset. It is estimated that ca. 95% of DDTs present in the atmosphere of Chinese cities was still from technical DDT, while only ca. approximately 5% was "dicofol-type of DDT". DDT application for public health control and DDT activated antifouling paint for fishing ships may be the two most important current sources of technical DDT. The DDT concentrations in several Chinese cities seem to match well with the reported DDT concentrations in human breast milk. A low TC/CC ratio was observed across China in the winter to spring, which may provide a fingerprint of Chinese chlordane emission. It was suggested that "weathered" chlordane emitted from urban construction foundations in winter may give the distinctively low TC/CC ratio. The data showed that China is an important global source for HCB. Higher HCB concentrations were observed in winter and spring, and in colder cities, highlighting an important contribution from combustion sources. Samples with higher endosulfan concentrations occurred in the cotton production areas, indicating its major use in killing cotton pests.

Chemical Biomarkers of Human Breast Milk Pollution

Human milk is, without question, the best source of nutrition for infants containing the optimal balance of fats, carbohydrates and proteins for developing babies. Breastfeeding provides a range of benefits for growth, immunity and development building a powerful bond between mother and her child. Recognition of the manifold benefits of breast milk has led to the adoption of breast-feeding policies by numerous health and professional organizations such as the World Health Organization and American Academy of Pediatrics.In industrially developed as well as in developing nations, human milk contamination by toxic chemicals such as heavy metals, dioxins and organohalogen compounds, however, is widespread and is the consequence of decades of inadequately controlled pollution. Through breastfeeding, the mother may transfer to the suckling infant potentially toxic chemicals to which the mother has previously been exposed.In the present review, environmental exposure, acquisition and current levels of old and emerging classes of breast milk pollutants are systematically presented. Although scientific evidences indicated that the advantages of breast-feeding outweigh any risks from contaminants, it is important to identify contaminant trends, to locate disproportionately exposed populations, and to take public health measures to improve chemical BM pollution as possible.

Contamination of soils with organochlorine pesticides in urban parks in Beijing, China

Urban parks are an integral component of healthy urban living. Since they are frequently visited, an understanding of the environmental quality of these urban facilities is crucial. Here, a study was conducted on the contamination of soils in the parks of Beijing. Organochlorine pesticides (OCPs), which have the potential to cause endocrine disturbances, were considered study objectives. Hexachlorocyclohexanes (HCHs) were found at concentrations of 0.2490-197.0 ng g(-1) and dichlorodiphenyltrichloroethanes (DDTs) were found at concentrations of 5.942-1039 ng g(-1) in the soils investigated. The preliminary pollution assessment indicated that DDTs have caused high pollution levels in the soils of some parks. Analysis of the sources of contamination showed that HCHs in the soils were derived from an old mixed source of technical HCHs and lindane and that DDTs, which were suspected to have recent application to the soils at some sites, were derived mainly from a mixture of technical DDTs and dicofol containing DDT impurities. An independent sample t-test proved that pesticides containing DDTs had been used in large amounts in the soils of parks before 1983 (p<0.05) and that the levels of DDTs in the soils of parks administered by the Beijing municipal government were significantly higher than the levels in those administered by the district government (p<0.05). However, the main difference in this situation needs to be further studied. This study suggested that open spaces like urban parks were not as sound as was expected and that there was potential for exposure of visitors/workers in the parks to organochlorine pesticides.

Distribution of HCHs and DDTs in soils from Beijing city, China

Concentrations of HCH isomers, DDT, and its metabolites have been measured in 63 soil samples collected in the urban area and outskirts of Beijing City. HCHs and DDTs were observed in all samples and their geometric mean levels were 5.78 and 38.21 ng g(-1), respectively. The spatial distribution of OCPs in Beijing was clearly showed by the contour map, suggesting the sites with the higher level of OCPs are located in the west and the south region and urban areas within the study regions." Furthermore, a t-test showed a significant difference of the level of some compounds between urban and outskirts areas. The temporal distribution of HCHs and DDTs suggested that the historical application of OCPs has a great effect on the residual level. The ratios of (alpha-/gamma -HCH (p,p'-DDE+p,p'-DDD)/p,p'-DDT, and o,p'-DDT/p,p'-DDT indicated the present of lindane and impure dicofol besides technical HCHs and technical DDTs in Beijing. The potential risk of HCHs and DDTs was assessed on the basis of some current guideline values for soil. The level of OCPs in our study area was compared with other studies.

Organochlorine pesticide residues in milk and blood of women from Anupgarh, Rajasthan, India

Anupgarh is the most fertile area of Rajasthan state where a variety of seasonal crops are grown. The availability of three manmade canals has enhanced the agricultural activities in this area. The farmers use huge amounts of pesticides to increase the crop productivity. Exposure of humans to these hazardous chemicals occurs directly in the fields and indirectly due to consumption of contaminated diet, or by inhalation or by dermal contact. The organochlorine pesticides are reported to be lipophilic and their presence in human milk and blood has been documented in different parts of the world. Blood and milk samples were collected from lactating women who were divided into four groups on the basis of different living standards viz residence area, dietary habits, working conditions and addiction to tobacco. The level of total organochlorine pesticides in blood ranged from 3.319mg/L-6.253mg/L while in milk samples it ranged from 3.209Mdash;4.608 mg/L. The results are in concurrence with the reports from other countries.

Levels of organochlorine pesticides in human milk from central Taiwan

The present study determined the residues of organochlorine pesticides (OCPs) in human milk collected in central Taiwan between December 2000 and November 2001. The OCPs were analyzed by GC/MS for 36 human milk samples from healthy women ranging between 20 and 36 years of age. The predominant OCPs were p,p'-DDE, p,p'-DDT, alpha-CHL, heptachlor epoxide, heptachlor, beta-HCH, and gamma-HCH, with median levels of 228, 19, 7.4, 4.0, 2.3, 1.2, and 0.8 ng/g lipid, respectively. The residues of OCPs in human milk from central Taiwan were comparable to those described in results from Sweden, the United Kingdom, and Japan, and were significantly lower than those from investigations in Asian countries, including China, Thailand, Indonesia, and Vietnam. Low DDE/DDT ratio (mean=13.6, SD=6.54) indicated that residual OCPs in human milk mainly originate from past exposure. A notable decrease in DDT levels ( sigma DDT=333 ng/g lipid) in human milk was found in this study compared to results from the previous two decades ( sigma DDT=3,595 ng/g lipid). Hypothetically, the level of alpha-CHL was significantly associated with total TEQ levels in Taiwanese human milk because of the sources of food contaminant, i.e. animal fat. Based on low OCP levels in Taiwanese human milk and low estimated median daily intake of total DDTs for a breastfed infant (1,358 ng/kg/day) with the assumption of an infant weighting 4 kg and consuming 699 g milk per day in the first month after birth, the Taiwanese policy of breast-feeding promotion was supported.

Persistent organic pollutants in human milk in women from urban and rural areas in northern China

Human milk specimens from 55 women in Shijiazhuang urban and Tangshan rural areas in Hebei Province in northern China were collected and analyzed for persistent organic pollutants, such as p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE), hexachlorobenzene (HCB), beta-hexachlorocyclohexane (beta-HCH), and dioxins. We administered a questionnaire to milk donors at collection time, asking about lifestyle factors that potentially influence organochlorine pesticide (OCP) levels in human milk. We found that the concentrations of p,p'-DDE and beta-HCH in human milk from the primiparous mothers in Shijiazhuang (3330 and 108.8 ng/g fat, respectively) were higher than in samples from mothers from Tangshan (1916 and 21.2 ng/g fat, respectively). In addition, we found the level of p,p'-DDE correlated positively with a dietary history of meat consumption or consumption of internal organs of pigs and sheep (r=0.38 and r=0.52, respectively), but not with intake frequencies of vegetables and fruits in primiparous mothers. The higher level for p,p'-DDE may be due to a greater intake of contaminated fatty foods in the industrialized areas. We also showed that the body burden of p,p'-DDE was higher in the urban group compared to the values in other regions in China after 1998. However, there was no difference in dioxin levels between the two regions. Comprehensive monitoring of persistent organic pollutants in human milk and food is needed in China.

A review on the usage of POP pesticides in China, with emphasis on DDT loadings in human milk

This article attempts to review the usage of nine pesticides included in the 12 Stockholm Convention persistent organic pollutants (POPs) in China and to examine the extent of DDT contamination in human milk, focusing on the Chinese populations. By comparing all the data available concerning DDTs in human milk from 19 countries, it is revealed that the Chinese populations exhibit rather high concentrations of DDTs, due to the fact that China has been a major producer and consumer of DDTs in the past, and also uses DDT for vector control, resulting in higher background levels of DDTs in different ecological compartments. The high body loading of DDT in Chinese populations is also related to the high dietary intake due to contamination of food. When comparing the data obtained recently (1998-2002), the coastal populations such as Guangzhou (DDE+DDT 2.13 microgg(-1) fat), Hong Kong (2.87 microgg(-1) fat) and Dalian (2.13 microgg(-1) fat) contain higher concentrations of DDTs which may reflect the dietary difference of consuming more meat and fish, than other Chinese populations (Beijing 1.96 microgg(-1) fat; Shenyang 0.87 microgg(-1) fat). In general, the rather low ratio of DDE/DDT (e.g., 4.07 for Guangzhou) of the Chinese milk samples reflected the more recent releases of DDT. It is recommended to impose a tighter control on the use of DDT for vector control as well as for agricultural application, conduct regular monitoring of DDT concentrations in different ecological compartments which include air, water, sediment and biota. Human milk is a preferred indicator reflecting human body loadings of POPs including DDTs, as well as the risk which may impose on our next generation. A national wide survey is needed to investigate the intake of POPs, including POP pesticides, due to dietary differences, with a strong focus on the more sensitive populations, e.g., coastal residents who consume a large amount of fish.