Multivariate models to predict human adipose tissue PCB concentrations in Southern Spain

[Endocrine disruptors and obesity: obesogens]

Incidence and prevalence of owerweight and obesity have greatly increased over the past three decades in almost all countries around the world. This phenomenon is not easily explained by lifestyle changes in populations with very different initial habits. This has led to consider the influence of other factors, the so-called endocrine disruptors, and more specifically obesogens. This study reviewed the available evidence about polluting chemical substances which may potentially be obesogens in humans: DES, genistein, bisphenol A, organotins (TBT, TPT), and phthalates. The first three groups of substances mainly act upon estrogen receptors, while organotins and phthalates activate PPARγ. It was concluded that evidence exists of the obesogenic effect of these chemical substances in tissues and experimental animals, but few data are available in humans.

Concentrations of organochlorine pesticides and polychlorinated biphenyls in human serum and adipose tissue from Bolivia

Organochlorine pesticides and polychlorinated biphenyls (PCBs) are synthetic chemicals that are highly resistant to biodegradation and have proven adverse health effects. The objectives of this study were to determine concentrations of three selected organochlorine pesticides (p,p'-DDT, p,p'-DDE, HCB) and three specific PCB congeners (PCB 138, 153, 180) in adipose tissue and serum samples from an urban adult population (n=112) in the city of Santa Cruz de la Sierra, Bolivia, and to investigate their relationships within and between the two matrices and with selected socio-demographic characteristics. The percentages of samples positive for these compounds ranged from 40% for PCB 180 to 100% for p,p'-DDE in adipose tissue, and from 21% for HCB to 93% for p,p'-DDE in serum. Median number of residues per sample was five for adipose tissue and three for serum. Geometric mean concentrations indicate a considerable historical and recent exposure to organochlorine pesticides and PCBs in this population. Adipose tissue:serum ratios ranged from 149.3 to 590.3 (wet basis) and from 0.9 to 3.5 (lipid basis). We found positive and statistically significant correlations between adipose tissue and serum concentrations only in p,p'-DDE and HCB. This novel study in Bolivia underlines the need for human biomonitoring to assess exposure to environmental pollutants in South America.

Contribution of sociodemographic characteristics, occupation, diet and lifestyle to DDT and DDE concentrations in serum and adipose tissue from a Bolivian cohort

The organochlorine pesticide p,p'-Dichlorodiphenyltrichloroethane (DDT) was widely used in the early 1960s-70s for vector control in tropical and subtropical areas of South America. Due to its persistence, DDT has a high potential to bioaccumulate in the food chain and living organisms and is a major public health concern, especially in South America. The main purpose of the present study was to investigate predictors of serum and adipose tissue concentrations of p,p'-DDT and its main metabolite, p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE), in an adult cohort (n=112) from Santa Cruz de la Sierra, Bolivia, using multiple linear regression models. These models explained 29.3-47.8% of the variability in adipose tissue concentrations of p,p'-DDT and p,p'-DDE, respectively, and 32.9-47.0% of that in serum. Main exposure predictors included age, occupational class, residence, diet, smoking habit, and accumulated breastfeeding time. This is one of the few studies to explore predictors of human exposure to these chemicals using a multivariate approach in a South American population. Results show that predictors of human exposure to p,p'-DDT and p,p'-DDE in Santa Cruz de la Sierra may diverge from those found in other populations of the world, due to particular sociodemographic and lifestyle characteristics of this region.

Polybrominated diphenyl ethers, polychlorinated biphenyls, and organochlorine pesticides in adipose tissues of Korean women

Studies on residue levels and accumulation profiles of persistent organic pollutants (POPs) in human adipose tissues of Korean populations are scarce. In this study, concentrations and accumulation features of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs) were measured in adipose tissues of Korean women age 40-68 years. The highest concentrations were found for PCBs and DDTs, which were 1-2 orders of magnitude greater than the concentrations of hexachlorocyclohexanes, chlordanes, and PBDEs. The concentrations of PCBs and OCPs were lower than those reported for other countries. However, PBDE concentrations were greater than those reported for other countries, suggesting that ongoing exposure to PBDEs is a concern in Korea. The profiles of PBDEs were characterized by the predominance of BDE 209, followed by nona- and octa-BDEs, which are consistent with the consumption patterns of products containing PBDEs in Korea. The concentrations of PCBs and some OCPs were significantly correlated with each other, whereas PBDEs showed low or moderate correlations with other POPs, suggesting differences in exposure routes and biotransformation potentials of the compounds studied. The concentrations of organochlorines and PBDEs were not correlated with subjects' age and body mass index. The results of this study provide baseline information on POPs in adipose tissues of the general population in Korea.

Empirical analyses of the influence of diet on human concentrations of persistent organic pollutants: a systematic review of all studies conducted in Spain

BACKGROUND

Numerous studies analyzed concentrations of persistent organic pollutants (POPs) in human samples, and in many types of foods; however, food consumption is less commonly included in studies on the determinants of POP concentrations in humans, and these approaches are rarely integrated with surveys of food intake to estimate the amount and safety of human POP intake from food.

OBJECTIVE

To analyze the main characteristics and findings of all studies conducted in Spain that quantitatively assessed the influence of diet on human concentrations of POPs.

METHODS

Studies published until December 2010 (with no other time restrictions) were identified through Medline/PubMed, ISI-Thomson, ScienceDirect, and SciELO databases.

RESULTS

We identified 25 papers, from 19 different studies. Twelve papers were published in 2009-2010. All studies but one were based on subgroups not representative of the general population, and over half were limited to women. Serum was the most used biological matrix, while p,p'-DDE, HCB and PCBs were the most frequently analyzed compounds. Food intakes were measured with heterogeneous food frequency questionnaires. The most consistent association was between fish consumption and PCBs and HCB, followed by dairy products and PCBs. A few studies observed a relationship between meat and some POPs, whilst intake of vegetables, fruits and cereals was rarely related to POP levels. Only 3 studies did not find any relationship between dietary habits and POP concentrations.

CONCLUSIONS

In spite of methodological heterogeneity, the studies were able to quantify to what extent consumption of foods from animal origin (fish, milk, dairy products and meat) is related to higher body concentrations of POPs. As in a few other countries, in Spain food consumption is increasingly analyzed as a major determinant of human POP intake.