[Concentrations of persistent toxic compounds in the Spanish population: a puzzle without pieces and the protection of public health]

Historical exposure to persistent organic pollutants and cardiovascular disease: A 15-year longitudinal analysis focused on pharmaceutical consumption in primary care

BACKGROUND

Despite restrictions on their production and use, most of the population is still exposed to Persistent Organic Pollutants (POPs), including organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). These chemicals are thought to contribute to the aetiology of highly prevalent chronic conditions, such as cardiovascular diseases (CVDs), although current evidences are still controversial.

OBJECTIVES

To explore the potential contribution of historical POP exposure to 15-year pharmaceutical consumption in relation to CVD.

METHODS

This study is framed within GraMo adult cohort. Participants (n = 387) were recruited in two hospitals in Granada province, Southern Spain (2003-2004). Historical exposure to 5 OCPs and 3 non-dioxine-like PCBs was estimated by analysing adipose tissue concentrations at recruitment. Pharmaceutical consumption from recruitment until year 2017 was quantified by reviewing dispensation databases. Average consumption increase (ACI) in CVD medication was calculated by subtracting average consumption in 2002 to the average yearly consumption during follow-up. ACI was expressed as Defined Daily Dose (DDD)/year units. Data analyses were carried out using a multivariable multinomial logistic regression and weighted quantile sum regression (WQS), with ACI categorized in quartiles (Q) as the dependent variable.

RESULTS

Concentrations of most pollutants showed a positive trend with the quartiles of ACI. Particularly, PCB-153 showed increasing and statistically significant odds ratios (ORs) for Q2 (OR: 1.27, 95% confidence interval (CI): 1.07-1.52), Q3 (OR: 1.49, 95 %CI: 1.17-1.88) and Q4 (OR: 1.42, 95 %CI: 1.13-1.78) vs Q1. Similarly, beta-hexachlorocyclohexane (β-HCH) also showed increasing ORs, that reached statistical significance in Q4 (OR: 1.36, 95 %CI: 1.06-1.74) vs Q1. These findings were corroborated by WQS analyses, that revealed a significant mixture effect, predominantly accounted for by PCB-153 and β-HCH.

DISCUSSION

Our results suggest that long-term POP exposure might represent a modifiable risk factor for CVD. These findings are relevant for public health campaigns and management, since pharmaceutical consumption is considered an indicator of both morbidity and health expenditure.

Differential contribution of animal and vegetable food items on persistent organic pollutant serum concentrations in Spanish adults. Data from BIOAMBIENT.ES project

Diet is considered the main source of Persistent Organic Pollutant (POP) exposure in the general population, although there are still several gaps of knowledge regarding the differential contribution of main food groups. The aim of this study was to identify dietary patterns that contribute to human exposure to organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and Perfluoroalkyl Substances (PFASs). Study population (n=1880, 18-65years old) was recruited during 2009-2010 in all the main geographical areas of Spain. For this work, exposure was estimated by chemical analyses of serum levels of 6 PCBs (n=1880), 13 OCPs (n=934), and 6 (PFASs) in a subsample of 755 (n=755). Dietary habits and covariates were gathered via self-administered questionnaires. Data analyses were performed by means of multivariable linear regression and weighted quantile sum regression. Both the consumption of animal-based and plant-based food were positively associated with the individual concentrations of p,p´-DDE, hexachlorobenzene, and PCB-congeners -138, -153, and-180. The contribution of animal-based products was 2.1-4.0× stronger except in p,p´-DDE, to which both patterns had similar contributions. In PFASs only animal food was positively associated with the exposure levels. The main animal-based contributors to PCB exposure were fish (49-64%) and eggs (19-36%), while OCP concentrations were mainly influenced by dairy products (32-48%) and fish (47-48%). PFOA and PFHxS were mainly explained by cold-meat (34-37%), fish (25-26%), and eggs (19-21%), while PFOS and PFDA were primarily influenced by fish consumption (44-77%). In the case of plant-based items, fruits (25-82%) and vegetables (18-63%) accounted for the majority of the variability of PCB and OCP concentrations. Our results highlight the relevance of dietary POP exposure as well as the need for the consideration of nutritional interventions in public health programs aiming to reduce POP exposure in the general population.

Associations of persistent organic pollutants in serum and adipose tissue with breast cancer prognostic markers

This study aimed to evaluate associations between exposure to a group of persistent organic pollutants, measured in both adipose tissue and serum samples from breast cancer patients, and a set of tumor prognostic markers. The study population comprised 103 breast cancer patients recruited in Granada, Southern Spain. Data for tumor prognostic markers were retrieved from hospital clinical records and socio-demographic information was gathered by questionnaire. Persistent organic pollutants were quantified by gas chromatography with electron capture detection. Exposure levels were categorized in quartiles, and associations were evaluated using unconditional logistic regression. Adipose tissue HCB concentrations were associated positively with ER and PR expression (p-trends=0.044 and 0.005, respectively) and negatively with E-Cadherin and p53 expression (p-trends=0.012 and 0.027, respectively). PCB-180 adipose tissue concentrations were positively associated with HER2 expression (p-trend=0.036). Serum PCB-138 concentrations were positively associated with ER and PR expression (p-trends=0.052 and 0.042, respectively). The risk of p53 expression was higher among women in the lowest quartile of serum PCB-138 concentrations, but no significant trend was observed (p-trend=0.161). These findings indicate that human exposure to certain persistent organic pollutants might be related to breast cancer aggressiveness. We also highlight the influence on exposure assessment of the biological matrix selected, given that both serum and adipose tissue might yield relevant information on breast cancer prognosis.

Effects of maternal diet and environmental exposure to organochlorine pesticides on newborn weight in Southern Spain

An appropriate eating pattern is essential during childbearing years and pregnancy to ensure a healthy pregnancy and newborn. Our group developed a Mediterranean Diet Score for Pregnancy (MDS-P) based on the MD and the specific need of pregnant women for Fe, Ca, and folic acid. Humans are daily exposed to endocrine disruptors, which may alter body weight and hormone system regulation. This study analyzed the relationship of maternal diet and in utero exposure to organochlorine pesticides (OCPs) with newborn weight in mothers and newborns from Southern Spain. Higher MDS-P score, folic acid supplementation, and greater in utero exposure to endosulfan-diol and endosulfan-1 were related to higher newborn weight. MDS-P score was not associated with maternal weight gain during pregnancy (above or below 12 Kg). Residues from one or more OCPs were detected in 96.5% of umbilical cord serum samples from 320 newborns. The most frequent residues were endosulfans (96.5%). The presence of endosulfan-diol, endosulfan-I, p-p´DDT, folic acid supplementation, and a higher MDS-P (>8) were predictive factors for newborn overweight (>3500 g). Conversely, smoking during pregnancy, shorter gestation time (32-36 vs. 37-39 weeks), and lesser maternal weight gain during pregnancy predicted lower newborn weight (<2500 g). These results indicate prenatal exposure to OCPs in Southern Spain and its possible impact on the weight of healthy full-term newborns. Further studies are warranted to interpret the consequences of this exposure and identify preventive measures. Adherence to the MD and folic acid supplementation during pregnancy emerged as predictive factors for overweight in newborns.

Historical exposure to persistent organic pollutants and risk of incident hypertension

The aim of this study was to assess the influence of adipose tissue concentrations of a group of persistent organic pollutants (POPs) on the risk of hypertension in an adult cohort of residents of Granada (Southern Spain) over a 10-year follow-up. No chemical was significantly associated with the risk of hypertension in the overall population or when models were stratified by sex or median age. However, we found positive associations between log-transformed POP concentrations and hypertension risk in participants with body mass index (BMI) above the median value of 26.3kg/m(2), which were statistically significant for hexachlorobenzene (HR=1.26, 95% CI=1.03-1.56), β-hexachlorocyclohexane (HR=1.25, 95% CI=1.03-1.51), and polychlorinated biphenyl congeners -138 (HR=1.32, 95% CI=1.04-1.69) and -153 (HR=1.36, 95% CI=1.00-1.84). Inverse associations were observed in the subgroup with BMI≤26.3kg/m(2), but none was statistically significant. More research and a longer follow-up period are warranted to verify these associations and elucidate the role of obesity as a potential effect modifier. Given the elevated worldwide frequency of POP exposure and hypertension, the public health impact of this relationship may be substantial.

Adipose tissue concentrations of persistent organic pollutants and total cancer risk in an adult cohort from Southern Spain: preliminary data from year 9 of the follow-up

There is an increasing trend in the incidence of cancer worldwide, and it has been accepted that environmental factors account for an important proportion of the global burden. The present paper reports preliminary findings on the influence of the historical exposure to a group of persistent organic pollutants on total cancer risk, at year 9 in the follow-up of a cohort from Southern Spain. A cohort of 368 participants (median age 51 years) was recruited in 2003. Their historical exposure was estimated by analyzing residues of persistent organic pollutants in adipose tissue. Estimation of cancer incidence was based on data from a population-based cancer registry. Statistical analyses were performed using multivariable Cox-regression models. In males, PCB 153 concentrations were positively associated with total cancer risk, with an adjusted hazard ratio (95% confidence interval) of 1.20 (1.01-1.41) for an increment of 100 ng/g lipid. Our preliminary findings suggest a potential relationship between the historical exposure to persistent organic pollutants and the risk of cancer in men. However, these results should be interpreted with caution and require verification during the future follow-up of this cohort.

Human exposure to p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) in urban and semi-rural areas in southeast Spain: a gender perspective

p,p'-Dichlorodiphenyldichloroethylene (p,p'-DDE) is the main metabolite of pesticide dichlorodiphenyltrichloroethane and a marker of past exposure to this organochlorine pesticide. p,p'-DDE is considered a persistent organic pollutant with potential adverse effects on human health. The aims of the present study were to assess p,p'-DDE levels in serum and adipose tissue from a cohort of adults in southern Spain and to explore the predictors of exposure from a gender perspective. Chemical analyses were performed using gas chromatography-coupled mass spectrometry in tandem mode. The study population (n=387) was intraoperatively recruited in two areas of Granada Province (southern Spain), and data on potential predictors of these concentrations were gathered by questionnaire. The statistical analysis was performed by means of multivariable linear regression models. All participants showed detectable concentrations of p,p'-DDE in both serum and adipose tissue, with median concentrations of 175.7 and 93.0 ng/g lipid, respectively (p<0.001), and the two measurements showed positive correlations. Women showed higher concentrations than men (115.8 and 66.2 ng/g lipid, respectively, p<0.001). Concentrations in both matrices were positively associated with fatty food consumption, as well as with age and BMI, the latter only in adipose tissue. The multivariate model showed that, among women, adipose tissue concentrations were approximately 40% higher in those residing in the semi-rural area and 2-fold higher in those whose mothers had participated in agricultural activities during the pregnancy. In this study population, gender and place of residence play a key role in human exposure to p,p'-DDE and can be used to identify subjects at special risk of long-term exposure.

Relationship between occupational social class and exposure to organochlorine pesticides during pregnancy

BACKGROUND

Little evidence is available on the influence of socioeconomic factors on exposure to persistent organic pollutants, especially during vulnerable periods such as pregnancy and early life.

OBJECTIVE

To investigate the relationship of maternal social class with placental concentrations of organochlorine pesticides (OCPs) and their combined estrogenic activity measured with a biomarker of exposure.

METHODS

Exposure to 16 OCPs (DDTs, endosulfans, and seven other compounds) and the total effective xenoestrogenic burden (TEXB) were analyzed in placentas from a mother-child cohort. OCP concentrations were quantified by gas chromatography and mass spectrometry, and TEXB was assessed with the E-Screen bioassay. Social class was classified according to maternal occupation. Multivariate regression analysis was conducted to examine variations in pesticide exposure and TEXB as a function of maternal social class in 257 subjects.

RESULTS

Placental p,p'-DDT concentrations were higher in social classes III and IV than in classes I-II (the most affluent); concentrations of the sum of DDTs were higher in class IV; and exposure to the sum of endosulfans was greater in class III. HCB concentrations were higher among women in class IV than in classes I-II and among manual (classes III-V) than non-manual workers. However, the trend across social classes was only statistically significant for HCB. Social class significantly explained 10% of the variability in concentrations of the sum of endosulfans.

CONCLUSION

There is a need to explore whether more disadvantaged populations suffer higher levels of exposure to pesticides or other environmental chemicals and how different social processes contribute to this exposure.

Persistent organic pollutants (POPs) in Africa: Egyptian scenario

Persistent organic pollutants (POPs) are organic (carbon-based) compounds that include synthesized substances (pesticides and polychlorinated biphenyls [PCBs]) and other by-product substances generated as a result of human and natural activity (dioxins and furans). Extensive scientific studies have shown that POPs are some of the most dangerous pollutants released into the environment by humans. Great efforts have been made since the early 1960s to enhance chemical management and safety issues. Various conventions have been adopted for this purpose: the Stockholm Convention (SC) is one of the well-known meetings in this context. The SC on POPs (May 2001) focuses on reducing and eliminating releases of 12 POPs coined the 'Dirty Dozen' by the United Nations Environment Program (UNEP). Persistence of such chemicals in soils, air, and water, together with natural processes such as evaporation to the atmosphere and washout by rain and flood, give rise to their ubiquitous distribution in the environment and eventual penetration into food chains and bio-accumulation in humans. Public concern about contamination by POPs increased recently because several of these compounds are identified as hormone disruptors, which can alter normal function of endocrine and reproductive systems in humans and wildlife. African countries are using pesticides, such as dichlorodiphenyltrichloroethane (DDT), lindane, toxaphene, endrin, dieldrin, heptachlor, since more than 50 years for combating agricultural pests and controlling disease vectors, especially malaria. The way in which pesticides are used in Africa caused serious environmental and health problems much more than elsewhere. These problems are represented by accumulation of organochlorine pesticide (OCP) residues in different environmental samples and hosting of at least 50,000 tons of obsolete pesticides, as well as tens of thousands of tons of contaminated soil. Within the framework of the Africa Stockpiles Program (ASP), huge quantities of pesticidal POPs have been completely or partially destroyed in a number of African countries (e.g. Egypt, Namibia, Niger, Senegal, Seychelles, South Africa, Sudan, Tanzania, Uganda, Zambia). At regional level (i.e. African Countries), a strategic plan for monitoring and getting rid of POPs in the continent should be set up and implemented through coordination between all governments. Among issues of top priorities are to find alternative non-combustion technologies for disposing obsolete pesticides, and to use alternative control measures for mosquitoes' management and other vector-borne diseases.

Chlorinated organic pesticides in marketed food: Barcelona, 2001-06

This paper reports concentration levels of 22 chlorinated organic compounds (both primary compounds and metabolites) in food marketed in the city of Barcelona (Catalonia, Spain) in 2001-06. Samples included meat products, fish and seafood, eggs, milk and dairy, vegetal oils, cereal products and derivates, vegetables, fresh fruits, dry fruits, spices, formula and baby food, tea and wine. Levels of chlorinated organic compounds were determined by gas chromatography with selective detectors: electron capture (ECD), flame photometric (FPD) and confirmation with mass-spectrometry. Chlorinated organic pesticides were detected in 7 of the 1,484 samples analyzed in the 2001-06 period (0.5%): 1 dairy product, 1 fruit, 1 olive oil and 4 vegetables. Specific pesticides detected are lindane and endosulfan alpha, beta or sulphate. A decrease in both the proportion of samples with detectable residues and in the variety of chlorinated pesticides found is visible when comparing these results with those of the previous 1989-2000 period. These results suggest the gradual disappearance of regulated chlorinated organic pesticides as a consequence of the growing worldwide implementation of current regulatory agreements.

Organochlorine pesticide exposure in children living in southern Spain

Despite the prohibition of most persistent organochlorine (OC) pesticides in Spain, their presence has been widely documented in adult human tissues. However, scarce information is available on the exposure of children. The aim of the present study was to investigate the presence of 16 OC pesticide residues in 52 fat samples collected from boys with a mean age of 7yr (0-15yr) living in Southern Spain and to assess the association between OC pesticide levels and child characteristics. No pesticide was found in more than 50% of samples, except for p,p'-DDE (79% of samples; median, 710ng/g lipid). After this compound, the most frequent pesticides were o,p'-DDT (17%; median, 330ng/g lipid) and o,p'-DDD (15%; median, 1510ng/g lipid). No statistically significant association was found between p,p'-DDE or SigmaDDTs and the birth year, birth weight, gestational age, infant feeding history or the age, weight, height or Quetelet Index at the time of sampling. The lack of correlation between the presence of the main metabolite p,p'-DDE and that of the parent compounds, o,p'-DDT and p,p'-DDT, suggests that children were exposed mainly to the metabolite rather than to the commercial pesticide, which was banned 30yr ago. In contrast, among currently used OCs, endosulfan was positively correlated with the presence of its metabolites, suggesting exposure to the commercial products. Further research is warranted to investigate the health consequence in children resulting from exposure to chemicals suspected of endocrine-disrupting effects.

Organic compounds temporal trends at some invertebrate species from the Balearics, Western Mediterranean

Concentrations of persistent organic pollutants (POPs) such as hexachlorobenzene (HCB), dichlore diphenyl trichloretane (DDT), polychlorinated biphenyls (PCBs), and gamma-hexachlorocyclohexane (gamma-HCH or lindane) were determined in tissue of marine benthic invertebrates such as Mytilus galloprovincialis, Chamelea gallina, Venus verrucosa, Lithophaga lithophaga and Paracentrotus lividus. Species were selected due to their habitat, trophic level, feeding behaviour and their consumption. Invertebrate species were systematically sampled from December 1996 to December 2005 from several sites along the Balearic Islands. The highest concentrations of PCBs (785ng/g lipid) were found in M. galloprovincialis while the lowest concentrations were found in the sea-urchin P. lividus (193ng/g lipid). Among the 7 PCB quantified congeners the higher values are mainly obtained for CB138 and CB153. All bivalves presented higher PCBs contents than the sea-urchin P. lividus are possibly linked with the bioaccumulation process of POPs throughout the food web and to differential detoxifying mechanisms. The concentration of SigmaDDT exceeds that of HCB and gamma-HCH at all species and sampling stations. DDT concentrations ranged from 0.4ng/g ww at the bivalve C. gallina in 2002, to values of 15.8ng/g ww at the bivalve L. lithophaga in 1998. The values obtained for the organic compounds (HCH, HCB, PCBs, DDT) depend upon the place and year of sampling and are compared to values found by other authors for the mussel M. galloprovincialis in other Mediterranean areas. gamma-HCH and HCB were found in lower concentrations than the other POPs.

[Evolution of health inequalities in Catalonia [Spain]]

OBJECTIVE

To analyze the evolution of social inequalities in health in Catalonia (Spain) in the last 20 years.

METHODS

Mortality in 354 small areas of Catalonia (288 cities in Catalonia and 66 health areas in the city of Barcelona) was analyzed for the 1984-98 period. Indicators of self-perceived health status, lifestyles, and health services utilization by social class and gender were compared for 1994 and 2002. Factors related to occupational health, immigration and health, environmental health, and policies to reduce social inequalities in health were also analyzed.

RESULTS

Although most health indicators improved, multiple inequalities in health were found in both 1994 and 2002. These inequalities were the same in 2002 as in 1994 or, in some cases, worse. The collectives with the worst indicators were persons living in the most deprived areas, those from disadvantaged social classes, women, and immigrants from low-income countries.

CONCLUSION

Social inequalities in health have persisted over the past 20 years in Catalonia. We present some recommendations on health information systems, research, and policies to reduce these inequalities.

Exposure of young men to organochlorine pesticides in Southern Spain

It has been hypothesized that endocrine disruptors and especially synthetic estrogenic environmental contaminants (xenoestrogens) are etiologic factors in the global decrease of sperm counts and other problems of the male reproductive tract, including cryptorchidism, hypospadias, and testicular cancer. This possibility has prompted research into the current and historical incidence of these diseases. The largest area of intensive greenhouse agriculture in Europe is near the Mediterranean coast of Southern Spain, where this activity has greatly expanded since the 1960s. We determined and compared levels of 14 organochlorine pesticides in the blood of 220 young males in Southern Spain. Aldrin, dieldrin, endrin, lindane, methoxychlor, endosulfans, and DDT and its metabolites were identified. Detectable concentrations of p,p'-DDE were found in 96% of serum samples. Among the remaining DDTs, o,p'-DDD was the most prevalent, detected in 65% of serum samples. Detectable concentrations of endosulfan I or II or their metabolites endosulfan-diol, or -sulfate were found in all samples; endosulfan-diol was the most frequently detected metabolite (92%) followed by sulfate. Results indicate that men of reproductive age in Southern Spain have been and are exposed to organochlorine pesticides. Because many of these chemicals have estrogenic and anti-androgenic activity, further research is warranted to interpret the male reproductive health consequences of this exposure.

Environmental and lifestyle factors for organochlorine exposure among women living in Southern Spain

Southern Spain has the largest area of intensive greenhouse agriculture in Europe, and may constitute a special case of occupational and female exposure, because this type of farming requires considerable pesticide use and employs many women. We measured adipose tissue levels of 14 organochlorine pesticides in 458 women living in this area and analyzed the relationship between pesticide level/presence and sociodemographic characteristics, reproductive history or life-style factors that may influence this exposure. Pesticide presence was determined by gas chromatography with electron-capture detector. All fat samples were positive for 1 residue. DDT or metabolites were found in 98.25%, with mean value of 660 ngg(-1) of lipid. p,p'-DDE level was higher in women who were older, with lower educational level or obese. Almost 70% had measurable levels of endosulfan and/or metabolites, with a mean total value of 38.8 ngg(-1) of lipid. Endosulfan-I exposure was higher in women with shorter residence in rural settings and more frequent in women with 3 children. 52.62% were exposed to 1 of aldrin-dieldrin-endrin group. Endrin was more frequent in women who were younger, with higher educational level or no agricultural working experience; dieldrin was more frequent in women who were older, with lower educational level or more children. Finally, lindane residues were found in 39.30%. Lindane levels were higher in women who breastfed longer or had more children. Research is required on women occupationally exposed to a selected group of organochlorine pesticides, especially those of reproductive age, as a basis for preventive action.

Exocrine pancreatic cancer: symptoms at presentation and their relation to tumour site and stage

INTRODUCTION

The need to detect pancreatic cancer at earlier stages is undisputed. We recorded the signs and symptoms of patients presenting with exocrine pancreatic cancer and evaluated their association with clinical characteristics such as tumour site and disease stage.

PATIENTS AND METHODS

All patients (n = 185) with exocrine pancreatic cancer newly diagnosed at five general hospitals in Eastern Spain were prospectively recruited over 5 years. Symptoms were elicited through personal interviews and signs were recorded by the attending physician on admission.

RESULTS

At diagnosis, one third of tumours of the pancreas head were in stage I and another third in stage IV. None of the tumours of the body and tail were in stage I, and over 80% were in stage IV (p < 0.001) . At presentation, the most frequent symptoms were asthenia (86%), anorexia (85%), weight-loss (85%), abdominal pain (79%), and choluria (59%). Cholestatic symptoms were more common in tumours affecting only the pancreatic head (p < 0.001) . There was a clear trend toward more localized tumours with increasing numbers of cholestatic signs (p < 0.001) . Asthenia, anorexia and weight-loss were unrelated to stage. An increased symptom-to-diagnosis interval was associated with more advanced stage (p = 0.048).

CONCLUSIONS

Proper attention to signs and symptoms, especially cholestasis, may help identify patients with pancreatic cancer at an earlier stage. Results also provide a current picture of the semiology of pancreatic cancer which could be of use in studies on the potential of proteomic tests in the early detection of this neoplasm.

Inadvertent exposure to organochlorine pesticides DDT and derivatives in people from the Canary Islands (Spain)

In 1998, one of the largest determinations of organochlorine pesticides in a representative sample of a Spanish population (682 serum samples from the Canary Islands) was made in the context of the "Canary Islands Nutrition Survey" (ENCA). In the Canary Islands, extensive farming areas have been developed in these last decades, with greenhouses dedicated to intensive cultivation using DDT in huge amounts. In Spain, similarly to other European countries, DDT was banned in the late 1970s. The pesticide residues in human serum are indicative of past and present exposure to them. Our objective is to point out the differences of pesticide contamination between islands; and together with this, if a connection could be established with gender, age, or habitat of subjects. Concentration of selected persistent organochlorine pollutants (p,p'-DDT, o,p'-DDT, p,p'-DDE, o,p'-DDE, p,p'-DDD, and o,p'-DDD) was measured with gas chromatography-electron capture detector. Almost all of the samples (99.3%) presented detectable levels of some DDT-derivatives, being p,p'-DDE the most frequently detected organochlorine. The median concentration of total DDT body burden, expressed in ng/g fat, present in the Canary Islands (370 ng/g fat) was similar to that found in other European countries, although it was noteworthy that a fourth of the population showed a total DDT body burden higher than 715 ng/g. Interestingly, statistical significant differences were found in serum levels of organochlorine pesticides between islands, being these levels higher in people from Tenerife and Gran Canaria (415 and 612 ng/g fat, respectively), the islands that present both highest population and highest surface devoted to intensive agriculture. As expected, serum levels of both total DDT body burden and p,p'-DDE increased with age. Statistically significant differences were also found in relation to gender, women showing higher levels of these organochlorine pesticides than men. One of the most relevant findings of this work is the presence of a very high DDT/DDE ratio in people from the Canary Islands, thus indicating a chronic exposure to DDT that persists nowadays. DDT and its derivatives are considered as xenoestrogens, and they have been linked to breast cancer. Having into account that the Canary Islands present high incidence and mortality for breast cancer, our results point to the possibility that these environmental contaminants may be playing a determining role that must be investigated in detail. The high levels of DDT and its derivatives in serum from people living in this Archipelago should be considered a matter of public health concern.

Exposure of women to organochlorine pesticides in Southern Spain

Organochlorine pesticides are lipophilic compounds that persist in the environment. Because of their lipid solubility and resistance to metabolism, some of these chemicals accumulate in human tissues. The largest area of intensive greenhouse agriculture in Europe is near the Mediterranean coast of Southern Spain, where this type of farming has greatly expanded since the 1960s. We determined and compared the levels of 15 organochlorine pesticides in the adipose tissue and blood of 200 women living in Southern Spain. Aldrin, dieldrin, endrin, lindane, methoxychlor, endosulfans, and DDT and its metabolites were identified. Detectable concentrations of p,p'-DDE were found in 100% of adipose tissue and serum samples. Among the remaining DDTs, p,p'-DDT was the most common, being detected in 39% of adipose tissue and 76.5% of serum samples, followed by endosulfans I and II, which also were found in both adipose tissue and serum samples but at lower concentrations. Endosulfans were followed in frequency by lindane, aldrin, and dieldrin. Endrin and methoxychlor were present at a much lower frequency compared to those of the other organochlorines. Serum concentrations of p,p'-DDE o,p'-DDD, and endosulfan -I, -sulfate, -lactone, and -diol were significantly correlated with their adipose tissue concentrations. No significant relationships were found between the serum and adipose tissue concentrations of the remaining nine compounds determined, raising doubts about the equivalent use of fat/serum samples for the exposure assessment of some pesticides in epidemiological studies. The results suggested that women of reproductive age in Southern Spain have been and are currently exposed to organochlorine pesticides. Because many of these chemicals can mobilize during pregnancy and lactation, further research is warranted to interpret the health consequences for the children of such exposure.

Plaguicidas en la dieta: aportando piezas al rompecabezas

OBJECTIVES

To improve information on exposure to pesticides through diet in Spain by reporting the results on 88 pesticide parameters in 1,109 food samples obtained between 1998 and 2003 as part of the Barcelona program for research on the health quality of foods.

MATERIAL AND METHOD

The results are presented by food groups. For fruits and vegetables, the results were compared with those for the previous period. Statistical comparisons were performed using the chi2 test.

RESULTS

Of the 1,109 samples, 116 were positive for pesticides (10.5%). Persistent chlorinated compounds were detected in 1.5% and other compounds were found in 14.4%. Positive results were concentrated in fruits, vegetables, spices, cereals and their derivatives. There were no positive results among vegetable oils, eggs or fish products, and almost none in dairy products and meats. Fruits contained the greatest number of pesticides but none were persistent. Vegetables contained fewer pesticides, but some of these were persistent chlorinated compounds. Comparison of the results for fruits and vegetables with those of the 1989-97 period revealed no significant trends.

CONCLUSIONS

Although a considerable number of samples contained pesticides, most of these were not persistent chlorinated compounds. The number of pesticides in fruits was notable.

Pesticide exposure and women's health

BACKGROUND

Research on pesticide-related health effects has been mostly focused in industrialized countries and in men. This paper discusses critical issues related to women's pesticide exposure and its effects on women's health.

METHODS

The literature on pesticides was reviewed with emphasis on data related to women. Attention was focused on research suggesting different conditions of exposure or different response to pesticides by sex. Studies on cancer and reproductive effects were used as illustrative examples.

RESULTS

Women are increasingly exposed to pesticides in developing countries, where women's poisoning and other pesticide-related injuries seem to be greatly underestimated. Many of the effects of pesticides in human health will be the same for men and women, but not always. Some organochlorine pesticides have been related to breast cancer in post-menopausal women. However, knowledge about other pesticides is much more limited. Epidemiological studies assessing maternal exposure to individual pesticides and abortion, fetal death, or congenital defects are not conclusive, although some suggestive associations have been observed.

CONCLUSIONS

Gender-sensitive research is needed to properly address the study of women's pesticide exposures and related adverse outcomes. A better understanding of potential gender-environment and sex-environment interactions related to pesticide exposure and health effects in women is needed.

[Changes in concentrations of organochloride compounds in women from Flix, Tarragona [Spain]]

The population of Flix (region of Ribera del Ebro, Tarragona) is highly exposed to hexachlorobenzene (HCB) due to the closeness of an electrochemical factory. Although the degree of HCB contamination in this population is still high, concentrations of HCB in the sera of women aged 18-40 years from 1997 to 1999 were 61% lower than those observed in 1994 (4.1 ng/ml vs. 10.6 ng/ml). Concentrations of dichlorodiphenyl dichloroethane (p,p'-DDE) and beta-hexachlorocyclohexane (beta-HCH) also decreased, although the difference was not statistically significant. In contrast, concentrations of polychlorinated biphenyls (PCB) in the period 1997-1999 showed a nonsignificant increase compared with those in 1994.

Persistent toxic substances and public health in Spain

In Spain, there are substantial gaps in available information about contamination of food, humans, and the environment by persistent toxic substances (PTSs), although studies have shown detectable concentrations of DDE, PCBs, hexachlorobenzene, or hexachlorocyclohexane in 80-100% of the population. Spain will soon try to implement the Stockholm treaty on persistent organic pollutants (POPs). A country that ratifies the treaty is required to develop a National Implementation Plan (NIP). Such NIPs should provide for studies of factors that influence body concentrations of PTSs in the population, and thus ultimately reduce PTS data gaps. Spain's PTS-related problems are similar to those of many other countries. Elucidation of their causes, consequences, and possible solutions will be of benefit beyond national boundaries.

[Perspectives on endocrine disruption]

Two decades ago, reports of alterations in the reproductive function of some wild animal species and clear evidence of human and animal exposure to chemical substances with hormonal activity agonist and antagonist generated what is known now as the hypothesis of endocrine disruption. This is an emerging environmental health problem that has challenged some of the paradigms on which the control and regulation of the use of chemical compounds is based. The need to include in routine toxicology tests new research objectives that specifically refer to the development and growth of species and to the homeostasis and functionality of hormonal systems, has served to complicate both the evaluation of new compounds and the re-evaluation of existing ones. The repercussions on regulation and international trade have not taken long to be felt. On both sides of the Atlantic, screening systems for endocrine disrupters have been designed and established, and research programmes have been launched to characterise and quantify adverse effects on human and animal health and to develop preventive measures.