[Chemical pollution, exposome and health in the Canary Islands population: An assessment of the situation.] / Contaminación química, exposoma y salud en la población de las Islas Canarias: una revisión sistemática de los estudios realizados y análisis de la situación.

OBJECTIVE: The set of exposures to chemical substances and their role as a cause of disease gives rise to the concept of the exposome, partially made up of chemical pollutants to which an individual is exposed, which is why, unlike the genome, it is an a priori modifiable factor, its study being crucial in terms of Public Health. The population of the Canary Islands has been studied in terms of its levels of chemical contamination, with numerous biomonitoring studies, which makes it necessary to characterise its exposome and its consequences in terms of disease, in order to implement specific corrective measures to minimize the impact on its health. METHODS: A review of scientific literature (MEDLINE and Scopus) was made, according to PRISMA criteria and PICO methodology, to include studies on biomonitoring of pollutants, or evaluating the effect of pollutants on diseases prevalent in the archipelago. RESULTS: Twenty-five studies, both population-based and hospital-based, were selected. The results show that the exposome is made up of at least 110 compounds or elements, 99 of which appear to be present from the intrauterine stage. The presence of chlorinated pollutants and metals stands out, which seems to be related to the high incidence of metabolic diseases (diabetes), cardiovascular diseases (hypertension) and certain types of neoplasms (breast cancer). In short, the consequences are conditioned by the genome of the exposed population, reinforcing the enormous importance of genome-exposome interactions in the development of pathologies. CONCLUSIONS: Our results indicate that it is necessary to establish corrective measures on the sources of pollution that modify the exposome of this population.

OBJETIVO: El conjunto de exposiciones a sustancias químicas y su papel como causa de enfermedad da lugar al concepto de exposoma, conformado parcialmente por contaminantes químicos a los que un individuo se ve expuesto. Por ello, a diferencia del genoma, es un factor a priori modificable, siendo su estudio crucial en materia de Salud Pública. La población del archipiélago canario ha sido estudiada en cuanto a sus niveles de contaminación química, con numerosos estudios de biomonitorización, lo que hace necesario caracterizar el exposoma de ésta y sus consecuencias en términos de enfermedad, para poder implementar medidas correctoras específicas que minimicen el impacto en su salud. METODOS: Se realizó una revisión de la literatura científica (MEDLINE y Scopus) de acuerdo con los criterios PRISMA y siguiendo la metodología PICO, para incluir estudios de biomonitorización de contaminantes, o que evaluaran el efecto de éstos en enfermedades prevalentes en el archipiélago. RESULTADOS: Se seleccionaron veinticinco estudios, tanto de base poblacional como de base hospitalaria. Los resultados demuestran que el exposoma lo conforman, como mínimo, 110 compuestos o elementos, 99 de los cuales parecen estar presentes desde la etapa intrauterina. Destaca la presencia de contaminantes clorados y metales, lo que parece relacionarse con la alta incidencia de enfermedades metabólicas (diabetes), cardiovasculares (hipertensión) y ciertos tipos de neoplasias (cáncer de mama). Aunque tales consecuencias vienen condicionadas por el genoma de la población expuesta, reforzando la enorme importancia de las interacciones genoma-exposoma en el desarrollo de patologías. CONCLUSIONES: Nuestros resultados indican que es necesario establecer medidas correctoras sobre las fuentes de contaminación que modifiquen el exposoma de esta población.

Contaminación química, exposoma y salud en la población de las Islas Canarias: una revisión sistemática de los estudios realizados y análisis de la situación / Chemical pollution, exposome and health in the Canary Islands population: An assessment of the situation

Fundamentos: El conjunto de exposiciones a sustancias químicas y su papel como causa de enfermedad da lugar al conceptode exposoma, conformado parcialmente por contaminantes químicos a los que un individuo se ve expuesto. Por ello, a diferenciadel genoma, es un factora priori modificable, siendo su estudio crucial en materia de Salud Pública. La población del archipiélagocanario ha sido estudiada en cuanto a sus niveles de contaminación química, con numerosos estudios de biomonitorización, lo quehace necesario caracterizar el exposoma de ésta y sus consecuencias en términos de enfermedad, para poder implementar medidascorrectoras específicas que minimicen el impacto en su salud.Métodos: Se realizó una revisión de la literatura científica (MEDLINE yScopus) de acuerdo con los criterios PRISMA y siguiendo lametodología PICO, para incluir estudios de biomonitorización de contaminantes, o que evaluaran el efecto de éstos en enfermedadesprevalentes en el archipiélago.Resultados: Se seleccionaron veinticinco estudios, tanto de base poblacional como de base hospitalaria. Los resultados de-muestran que el exposoma lo conforman, como mínimo, 110 compuestos o elementos, 99 de los cuales parecen estar presentes desdela etapa intrauterina. Destaca la presencia de contaminantes clorados y metales, lo que parece relacionarse con la alta incidencia deenfermedades metabólicas (diabetes), cardiovasculares (hipertensión) y ciertos tipos de neoplasias (cáncer de mama). Aunque talesconsecuencias vienen condicionadas por el genoma de la población expuesta, reforzando la enorme importancia de las interaccionesgenoma-exposoma en el desarrollo de patologías.Concluiones: Nuestros resultados indican que es necesario establecer medidas correctoras sobre las fuentes de contamina-ción que modifiquen el exposoma de esta población.(AU)

Background: The set of exposures to chemical substances and their role as a cause of disease gives rise to the concept of theexposome, partially made up of chemical pollutants to which an individual is exposed, which is why, unlike the genome, it is an a priorimodifiable factor, its study being crucial in terms of Public Health. The population of the Canary Islands has been studied in terms ofits levels of chemical contamination, with numerous biomonitoring studies, which makes it necessary to characterise its exposomeand its consequences in terms of disease, in order to implement specific corrective measures to minimize the impact on its health.Methods: A review of scientific literature (MEDLINE and Scopus) was made, according to PRISMA criteria and PICO methodology, toinclude studies on biomonitoring of pollutants, or evaluating the effect of pollutants on diseases prevalent in the archipelago.Results: Twenty-five studies, both population-based and hospital-based, were selected. The results show that the exposome is madeup of at least 110 compounds or elements, 99 of which appear to be present from the intrauterine stage. The presence of chlorinated po-llutants and metals stands out, which seems to be related to the high incidence of metabolic diseases (diabetes), cardiovascular diseases(hypertension) and certain types of neoplasms (breast cancer). In short, the consequences are conditioned by the genome of the exposedpopulation, reinforcing the enormous importance of genome-exposome interactions in the development of pathologies.Conclusions: Our results indicate that it is necessary to establish corrective measures on the sources of pollution that modifythe exposome of this population.(AU)

Exposure to polycyclic aromatic hydrocarbons (PAHs) and bladder cancer: evaluation from a gene-environment perspective in a hospital-based case-control study in the Canary Islands (Spain).

BACKGROUND: Exposure to polycyclic aromatic hydrocarbons (PAHs) has been linked to bladder cancer. OBJECTIVE: To evaluate the role of PAHs in bladder cancer, PAHs serum levels were measured in patients and controls from a case-control study. METHODS: A total of 140 bladder cancer patients and 206 healthy controls were included in the study. Sixteen PAHs were analyzed from the serum of subjects by gas chromatography-mass spectrometry. RESULTS: Serum PAHs did not appear to be related to bladder cancer risk, although the profile of contamination by PAHs was different between patients and controls: pyrene (Pyr) was solely detected in controls and chrysene (Chry) was exclusively detected in the cases. Phenanthrene (Phe) serum levels were inversely associated with bladder cancer (OR = 0·79, 95%CI = 0·64-0·99, P = 0·030), although this effect disappeared when the allelic distribution of glutathione-S-transferase polymorphisms of the population was introduced into the model (multinomial logistic regression test, P = 0·933). Smoking (OR = 3·62, 95%CI = 1·93-6·79, P<0·0001) and coffee consumption (OR = 1·73, 95%CI = 1·04-2·86, P = 0·033) were relevant risk factors for bladder cancer. CONCLUSIONS: Specific PAH mixtures may play a relevant role in bladder cancer, although such effect seems to be highly modulated by polymorphisms in genes encoding xenobiotic-metabolizing enzymes.

Blood pressure in relation to contamination by polychlorobiphenyls and organochlorine pesticides: Results from a population-based study in the Canary Islands (Spain).

BACKGROUND: Epidemiological studies have reported significant associations between exposure to persistent organic pollutants (POPs) and increased blood pressure (BP). Environmental exposure to POPs, mainly organochlorine pesticides, is of concern to the population of the Canary Islands, who display a high prevalence of diseases associated with hypertension such as metabolic syndrome, obesity and cardiovascular disease. OBJECTIVE: We performed this population-based study in a representative population sample from this archipelago to evaluate whether serum levels of selected POPs could be considered as hypertension risk factors. METHODS: BP and several other well-known factors related to hypertension (gender, age, smoking, BMI, and total lipids) were recorded in 428 adult participants from the Canary Islands Nutritional Survey. In total, 28 POPs (including 18 polychlorinated biphenyl (PCB) congeners and 10 organochlorine pesticides and metabolites) were measured in the serum of the population enrolled in this survey. RESULTS: In total, 167 subjects (39%) demonstrated hypertension or used antihypertensive medication. We observed a positive association between systolic and diastolic BP and p,p'-DDE (r=0.222; p<0.001, and r=0.123; p=0.015, respectively). Conversely, an inverse association between systolic BP and aldrin was observed (r=-0.120; p=0.017). After adjusting for known confounders, only aldrin was inversely related to hypertension risk [OR: 0.28 (95% CI: 0.09-0.92); p=0.037]. After excluding subjects undergoing anti-hypertensive treatment, we also observed that aldrin was inversely associated with systolic BP in multivariate analyses, especially in men [OR: 0.126 (95% CI: 0.021-0.763); p=0.024]. CONCLUSION: Although it has been postulated that background POPs exposure may play a relevant role on elevated BP, we did not observed increased hypertension risk in relation to serum POPs in this cross-sectional study. Conversely, the cyclodiene pesticide aldrin was negatively associated with hypertension, suggesting that cyclodienes could exert an effect opposite of the DDT metabolites. These findings agree with other previous works indicating that POPs may induce divergent actions on BP and suggest that the direction of the association between BP and POPs could be dependent on the chemical structure as well as concentration of the evaluated POP. Prospective studies are needed to clarify the effect exerted by POPs on BP.

Consumption of foods of animal origin as determinant of contamination by organochlorine pesticides and polychlorobiphenyls: results from a population-based study in Spain.

The level of contamination with persistent organic pollutants (POPs) and dietary habits and food consumption was extensively studied in the population from the Canary Islands (Spain). Because foodstuffs of animal origin are well known to be prominent contributors to these contaminants, the current study aimed to assess the role of the dietary intake of animal products as a probability factor for increased serum POPs. The intake of animal products (dietary variables) as a determining factor for serum POP levels was investigated using multivariate statistical models. Our results showed that while poultry, rabbit, and cheese consumption increases the probability of having high levels of non-DDT-derivative pesticides, sausage, yogurt, lard, and bacon consumption decreases the probability of having high levels of these pesticides. In addition, poultry, rabbit, eggs, cream, and butter consumption increased the probability of having detectable levels of marker PCB, while dairy desserts decreased the probability of having detectable levels of these PCBs. On the contrary, sausage and meat consumption increased the probability of having detectable levels of dioxin-like PCBs (DL-PCBs). The current results confirm that dietary intake of foodstuffs of animal origin is a relevant risk factor for the accumulation of POPs (and therefore their serum levels). Our study indicates that the analysis of dietary patterns may be useful for identifying those individuals that will probably present a high body burden of POPs. Because POPs can exert deleterious effects on human health, the identification of populations at risk of being highly contaminated is mandatory in order to implement policies that minimize the exposure to these compounds.

Complex organochlorine pesticide mixtures as determinant factor for breast cancer risk: a population-based case-control study in the Canary Islands (Spain).

BACKGROUND: All the relevant risk factors contributing to breast cancer etiology are not fully known. Exposure to organochlorine pesticides has been linked to an increased incidence of the disease, although not all data have been consistent. Most published studies evaluated the exposure to organochlorines individually, ignoring the potential effects exerted by the mixtures of chemicals. METHODS: This population-based study was designed to evaluate the profile of mixtures of organochlorines detected in 103 healthy women and 121 women diagnosed with breast cancer from Gran Canaria Island, and the relation between the exposure to these compounds and breast cancer risk. RESULTS: The most prevalent mixture of organochlorines among healthy women was the combination of lindane and endrin, and this mixture was not detected in any affected women. Breast cancer patients presented more frequently a combination of aldrin, dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD), and this mixture was not found in any healthy woman. After adjusting for covariables, the risk of breast cancer was moderately associated with DDD (OR = 1.008, confidence interval 95% 1.001-1.015, p = 0.024). CONCLUSIONS: This study indicates that healthy women show a very different profile of organochlorine pesticide mixtures than breast cancer patients, suggesting that organochlorine pesticide mixtures could play a relevant role in breast cancer risk.

Background levels of polychlorinated biphenyls in the population of the Canary Islands (Spain).

Polychlorinated biphenyls (PCBs) are persistent and toxic compounds that have been detected in human serum or tissues worldwide. The objective of our study was to determine serum PCB levels in a representative sample of the general population of the Spanish Archipelago of the Canary Islands (607 serum samples from subjects aged between 6 and 75 years) in order to establish the main causes of this contamination and to evaluate the potential risks posed by these chemicals on the population through the use of toxicity equivalence to dioxins (TEQs). PCB congeners (28, 52, 77, 81, 101, 105, 114, 118, 123, 126, 138, 153, 156, 157, 167, 169, 180, and 189) were measured by gas chromatography-mass spectrometry (GC/MS). Our results showed that PCB residues were found in 76% of serum samples analyzed, with the congeners 153 and 180 being the most frequently detected and having the highest median values (21.8 and 6.7 ng/g lipid, respectively). Serum levels of non-dioxin-like PCBs increased with age, body mass index (BMI), urban habitat, and smoking. The median concentration of the sum of PCBs considered as markers of environmental contamination by these chemicals (M-PCBs) was 46.4 ng/g lipid. Levels of the sum of dioxin-like PCBs (DL-PCBs) were 48.5 ng/g lipid in the 95th percentile, and were also positively associated with age. As a consequence, age seemed to be positively associated with TEQs levels, reaching values as high as 58.6 pg/g lipid in the serum samples from oldest people. Our results indicate that the inhabitants of the Canary Archipelago show levels of PCB contamination lower than other populations present on the Spanish mainland, as well as many populations from developed countries. Nevertheless, as these compounds may induce adverse health effects even at very low doses, our findings should be considered by local Public Health authorities in order to establish measures for diminishing the exposure of the population of these islands to PCBs.

Associations between lactase persistence and the metabolic syndrome in a cross-sectional study in the Canary Islands.

BACKGROUND: The single nucleotide polymorphism (SNP) LCT -13910 C>T, associated with genetically determined phenotypes of lactase persistence (LP) or non-persistence (LNP), was studied in relation to the metabolic syndrome (MS). AIM OF THE STUDY: The aim was to determine if milk intake and MS are associated. We applied Mendelian randomization (MR). The SNP, LCT -13910 C>T, with the genotypes LP (TT/CT) and LNP (CC), was taken as a proxy for milk consumption. METHODS: A representative sample of adults belonging to the Canary Islands Nutrition Survey (ENCA) in Spain aged 18-75 years (n = 551) was genotyped for the LCT -13910 C>T polymorphism. We used the International Diabetes Federation (IDF) criteria to define MS. RESULTS: 60% of the population was LP and 40% LNP. One hundred seven LP subjects (35.0%) and 53 LNP subjects (25.6%) showed MS (chi (2) = 5.04, p = 0.025). LP subjects showed a significantly higher odds ratio (OR) for MS than LNP subjects computed for the whole population: both the crude OR (1.56; 95% CI 1.06-2.31) and adjusted OR for sex, age, daily energy intake, physical activity and educational level (1.57; 95% CI 1.02-2.43). Adjusted OR for women with LP was 1.93; 95% CI 1.06-3.52. CONCLUSIONS: The T allele of the SNP might constitute a nutrigenetic factor increasing the susceptibility of LP subjects, especially women, to develop MS in the Canary Islands.

Insulin-like growth factor-I (IGF-I) serum concentrations in healthy children and adolescents: relationship to level of contamination by DDT-derivative pesticides.

CONTEXT: Serum levels of Insulin-like growth factor I (IGF-I) play a critical role in children growth and in the pathogenesis of several diseases. In addition, recent studies suggest that DDT-derivative organochlorine pesticides (OC-DDTs) could influence IGF levels in human beings. OBJECTIVE AND DESIGN: Because it has been suggested that IGF-I peak levels at puberty could determine IGF-I levels in adulthood, we developed a cross-sectional study of the potential association between serum levels of OC-DDTs and IGF system in 160 serum samples from young people (81 boys and 79 girls) living in the Canary Islands (Spain). RESULTS: Multivariate tests were used adjusting for confounding variables (age, height, and weight) and stratifying by gender and age: IGF-I serum levels were significantly lower in pre-pubertal male children (6-15years) who showed detectable values of p,p'-DDE, and p,p'-DDD than in pre-pubertal male children with undetectable levels of these OC-DDTs-metabolites (p=0.023 and p=0.049, respectively). In addition, in this multivariate model, a non-linear dose-response curve was observed between Total DDT body burden (sum of the three DDT-derivatives measured: p,p'-DDT, p,p'-DDE, and p,p'-DDD) and IGF-I in pre-pubertal male children (6-15years; p=0.043). CONCLUSION: These findings suggest that OC-DDTs could modulate the IGF-system in a way that is highly influenced by gender and age. Improvements in our understanding of exogenous determinants of the IGF-system may provide new insights into the role played by environmental contaminants in IGF-related diseases.

Serum levels of insulin-like growth factor-I in relation to organochlorine pesticides exposure.

CONTEXT: Insulin-like growth factor 1 (IGF-I) and organochlorine pesticides (OCs) have been involved in the pathogenesis of several diseases like cancer, diabetes and growth disorders. OBJECTIVE AND DESIGN: The potential relationship between the serum levels of various OCs and serum IGF-I was investigated in adults (176 men and 247 women) from a representative sample of the general population of the Canary Islands (Spain). RESULTS: After adjustment for potential confounders, which include body mass index, age, and IGF-binding protein-3 (IGFBP-3), IGF-I levels were significantly lower in the 247 women who showed detectable levels of p,p'-DDD (a DDT-metabolite) than in women who presented non-detectable levels of this pesticide (p=0.030), specially in 36-50 years old women. A similar negative relationship was also found between IGF-I and aldrin (a non-DDT-derivative) in women (p=0.049). In the group of 176 men, aldrin seemed to exert a similar negative effect on IGF-I (p=0.046) and this effect was clearly significant in the oldest group (51-65 years) (p=0.009). A non-linear dose-response curve was observed between Total Cyclodienes Body Burden (Total Cyclodienes; sum of aldrin, dieldrin and endrin) and IGF-I in men (p=0.024). These findings suggest that OCs could modulate the IGF-system in a way that is highly influenced by gender, age and by chemical or combination of chemicals implicated. Such circumstances may contribute to the development of a number of diseases related to IGF-I and should be taken into account in public health decisions.

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.

[Hospital resources and myocardial infarction case fatality. The IBERICA study]. / Recursos hospitalarios y letalidad por infarto de miocardio. Estudio IBERICA.

INTRODUCTION AND OBJECTIVES: To determine the proportion of patients with myocardial infarction (MI) not admitted to a coronary care unit (CCU), the variables associated with admission into a CCU, and whether admission to a CCU, and the availability of coronary angiography in the same hospital, were associated with 28-day case fatality. PATIENTS AND METHOD: Population-based registry of MI in patients 25 to 74 years of age, admitted during 1996-1998. Demographic and clinical characteristics were recorded, as well as management, clinical course and survival after 28 days. Hospitals were classified according to the availability of a CCU and catheterization laboratory (advanced hospital), CCU only (intermediate hospital) or neither (basic hospital). Admission to the CCU was also recorded. RESULTS: In all, 9046 cases of MI were recorded; in 11.3% the patient was not admitted to a CCU. Age, smoking (OR=1.33; 95% CI, 1.08-1.64), non-Q MI (OR=0.62; 95% CI, 0.49-0.78) or undetermined location of MI (OR=0.34; 95% CI, 0.23-0.50), Killip 4 score on admission (OR=0.63; 95% CI, 0.40-1.00) and delay in arrival at the hospital >6 h were associated with CCU admission. Patients admitted to a CCU showed a lower case fatality in the first 24 h (4.2% vs 23.5%), which was independent of comorbidity, severity and treatment. The 24-hour survivors admitted to a basic hospital had higher case fatality (17.3% vs 7.8%) than other groups, which was related to differences in treatment. CONCLUSIONS: CCU admission is associated with a lower case fatality in the first 24 h. Admission to a basic hospital is associated with a higher 28-day case fatality even in patients who survive 24 h.