Modifying effect of urban parks on socioeconomic inequalities in diabetes prevalence: a cross-sectional population study of Madrid City, Spain

BACKGROUND

Evidence has shown contradicting results on how the density of urban green spaces may reduce socioeconomic inequalities in type 2 diabetes (equigenic hypothesis). The aim of this study is to test whether socioeconomic inequalities in diabetes prevalence are modified by park density.

METHODS

We designed a population-wide cross-sectional study of all adults registered in the primary healthcare centres in the city of Madrid, Spain (n=1 305 050). We obtained georeferenced individual-level data from the Primary Care Electronic Health Records, and census-tract level data on socioeconomic status (SES) and park density. We modelled diabetes prevalence using robust Poisson regression models adjusted by age, country of origin, population density and including an interaction term with park density, stratified by gender. We used this model to estimate the Relative Index of Inequality (RII) at different park density levels.

FINDINGS

We found an overall RII of 2.90 (95% CI 2.78 to 3.02) and 4.50 (95% CI 4.28 to 4.74) in men and women, respectively, meaning that the prevalence of diabetes was three to four and a half times higher in low SES compared with high SES areas. These inequalities were wider in areas with higher park density for both men and women, with a significant interaction only for women (p=0.008).

INTERPRETATION

We found an inverse association between SES and diabetes prevalence in both men and women, with wider inequalities in areas with more parks. Future works should study the mechanisms of these findings, to facilitate the understanding of contextual factors that may mitigate diabetes inequalities.

The association of age at menarche and adult height with mammographic density in the International Consortium of Mammographic Density

BACKGROUND

Early age at menarche and tall stature are associated with increased breast cancer risk. We examined whether these associations were also positively associated with mammographic density, a strong marker of breast cancer risk.

METHODS

Participants were 10,681 breast-cancer-free women from 22 countries in the International Consortium of Mammographic Density, each with centrally assessed mammographic density and a common set of epidemiologic data. Study periods for the 27 studies ranged from 1987 to 2014. Multi-level linear regression models estimated changes in square-root per cent density (√PD) and dense area (√DA) associated with age at menarche and adult height in pooled analyses and population-specific meta-analyses. Models were adjusted for age at mammogram, body mass index, menopausal status, hormone therapy use, mammography view and type, mammographic density assessor, parity and height/age at menarche.

RESULTS

In pooled analyses, later age at menarche was associated with higher per cent density (β√PD = 0.023 SE = 0.008, P = 0.003) and larger dense area (β√DA = 0.032 SE = 0.010, P = 0.002). Taller women had larger dense area (β√DA = 0.069 SE = 0.028, P = 0.012) and higher per cent density (β√PD = 0.044, SE = 0.023, P = 0.054), although the observed effect on per cent density depended upon the adjustment used for body size. Similar overall effect estimates were observed in meta-analyses across population groups.

CONCLUSIONS

In one of the largest international studies to date, later age at menarche was positively associated with mammographic density. This is in contrast to its association with breast cancer risk, providing little evidence of mediation. Increased height was also positively associated with mammographic density, particularly dense area. These results suggest a complex relationship between growth and development, mammographic density and breast cancer risk. Future studies should evaluate the potential mediation of the breast cancer effects of taller stature through absolute breast density.

A deep learning framework to classify breast density with noisy labels regularization

BACKGROUND AND OBJECTIVE

Breast density assessed from digital mammograms is a biomarker for higher risk of developing breast cancer. Experienced radiologists assess breast density using the Breast Image and Data System (BI-RADS) categories. Supervised learning algorithms have been developed with this objective in mind, however, the performance of these algorithms depends on the quality of the ground-truth information which is usually labeled by expert readers. These labels are noisy approximations of the ground truth, as there is often intra- and inter-reader variability among labels. Thus, it is crucial to provide a reliable method to obtain digital mammograms matching BI-RADS categories. This paper presents RegL (Labels Regularizer), a methodology that includes different image pre-processes to allow both a correct breast segmentation and the enhancement of image quality through an intensity adjustment, thus allowing the use of deep learning to classify the mammograms into BI-RADS categories. The Confusion Matrix (CM) - CNN network used implements an architecture that models each radiologist's noisy label. The final methodology pipeline was determined after comparing the performance of image pre-processes combined with different DL architectures.

METHODS

A multi-center study composed of 1395 women whose mammograms were classified into the four BI-RADS categories by three experienced radiologists is presented. A total of 892 mammograms were used as the training corpus, 224 formed the validation corpus, and 279 the test corpus.

RESULTS

The combination of five networks implementing the RegL methodology achieved the best results among all the models in the test set. The ensemble model obtained an accuracy of (0.85) and a kappa index of 0.71.

CONCLUSIONS

The proposed methodology has a similar performance to the experienced radiologists in the classification of digital mammograms into BI-RADS categories. This suggests that the pre-processing steps and modelling of each radiologist's label allows for a better estimation of the unknown ground truth labels.

Sleep duration and napping in relation to colorectal and gastric cancer in the MCC-Spain study

Sleep duration is a novel and potentially modifiable risk factor for cancer. We evaluated the association of self-reported sleep duration and daytime napping with odds of colorectal and gastric cancer. We included 2008 incident colorectal cancer cases, 542 gastric cancer cases and 3622 frequency-matched population controls, recruited in the MCC-Spain case-control study (2008-2013). Sleep information, socio-demographic and lifestyle characteristics were obtained through personal interviews. Multivariable adjusted logistic regression models were used to estimate odds ratios (OR) with 95% confidence intervals (CI) for cancer, across categories of sleep duration (≤ 5, 6, 7, 8, ≥ 9 hours/day), daytime napping frequency (naps/week) and duration (minutes/nap). Compared to 7 hours of sleep, long sleep was associated with increased odds of colorectal (OR≥9 hours: 1.59; 95%CI 1.30-1.94) and gastric cancer (OR≥9 hours: 1.95; 1.37-2.76); short sleep was associated with increased odds of gastric cancer (OR≤5 hours: 1.32; 0.93-1.88). Frequent and long daytime naps increased the odds of colorectal (OR6-7 naps/week, ≥30 min: 1.32; 1.14-1.54) and gastric cancer (OR6-7 naps/week, ≥30 min: 1.56; 1.21-2.02). Effects of short sleep and frequent long naps were stronger among participants with night shift-work history. Sleep and circadian disruption may jointly play a role in the etiology of colorectal and gastric cancer.

Arsenic, cadmium, and selenium exposures and bone mineral density-related endpoints: The HORTEGA study

BACKGROUND AND OBJECTIVES

Experimental data suggest that trace elements, such as arsenic (As), cadmium (Cd), and selenium (Se) can influence the bone remodeling process. We evaluated the cross-sectional association between As, Cd, and Se biomarkers with bone mineral density (BMD) measured at the calcaneus, in a representative sample of a general population from Spain. As secondary analyses we evaluated the associations of interest in subgroups defined by well-established BMD determinants, and also conducted prospective analysis of osteoporosis-related incident bone fractures restricted to participants older than 50 years-old.

METHODS

In N = 1365 Hortega Study participants >20 years-old, urine As and Cd were measured by inductively coupled-plasma mass spectrometry (ICPMS); plasma Se was measured by atomic absorption spectrometry (AAS) with graphite furnace; and BMD at the calcaneus was measured using the Peripheral Instaneuous X-ray Imaging system (PIXI). As levels were corrected for arsenobetaine (Asb) to account for inorganic As exposure.

RESULTS

The median of total urine As, Asb-corrected urine As, urine Cd, and plasma Se was 61.3, 6.53 and 0.39 μg/g creatinine, and 84.9 μg/L, respectively. In cross-sectional analysis, urine As and Cd were not associated with reduced BMD (T-score < -1 SD). We observed a non-linear dose-response of Se and reduced BMD, showing an inverse association below ~105 μg/L, which became increasingly positive above ~105 μg/L. The evaluated subgroups did not show differential associations. In prospective analysis, while we also observed a U-shape dose-response of Se with the incidence of osteoporosis-related bone fractures, the positive association above ~105 μg/L was markedly stronger, compared to the cross-sectional analysis.

CONCLUSIONS

Our results support that Se, but not As and Cd, was associated to BMD-related disease. The association of Se and BMD-related disease was non-linear, including a strong positive association with osteoporosis-related bone fractures risk at the higher Se exposure range. Considering the substantial burden of bone loss in elderly populations, additional large prospective studies are needed to confirm the relevance of our findings to bone loss prevention in the population depending on Se exposure levels.

Serum phospholipids fatty acids and breast cancer risk by pathological subtype: EpiGEICAM study

e13604

Background: The role of fatty acids (FA) in breast cancer (BC) etiology is unclear. Most studies are based on self-reported dietary intake, without considering their internal transformation. This analysis tries to assess whether serum levels of 26 phospholipid FA (PL-FAs) and markers of their endogenous metabolism are associated with BC risk, both globally and by pathological BC subtype. Methods: EpiGEICAM-01 is a Spanish multicenter matched case-control study. BC cases and healthy women completed a lifestyle and a food frequency questionnaire, and serum samples were collected. Serum PL-FAs percentages were measured by gas chromatography-mass spectrometry (GC–MS). Conditional and multinomial logistic regression models were used to quantify the association of PL-FAs tertiles with BC risk, overall and by pathologic BC subtypes [luminal, HER2+ and triple negative]. Models were adjusted for age and region (multinomial models), education level, body mass index (BMI), menopausal status, age at menarche and at first birth, hormone replacement therapy, alcohol consumption, last year physical activity, history of benign breast disease, family history of BC and caloric intake, and were corrected for multiple testing. Stratified analyses by BMI and menopausal status were also performed. Results: Questionnaires and serum samples were collected from 795 case-control pairs. Women with high serum levels of stearic acid [odds ratio (OR)T3vsT1= 0.44; 95% confidence interval (CI) = 0.30-0.66], linoleic acid (ORT3vsT1= 0.66; 95% CI = 0.49-0.90) and arachidonic to dihomo-γ-linolenic acids ratio (OR T3vsT1= 0.64 95%; CI = 0.48-0.84; differences were remarkable in overweight/obese women) presented lower BC risk. Participants with high concentrations of palmitoleic acid (ORT3vsT1= 1.65; 95% CI = 1.20-2.26), trans-ruminant palmitelaidic acid (ORT3vsT1= 1.51; 95% CI = 1.12-2.02; differences observed were noticeable both in postmenopausal and in overweight/obese women), trans-industrial elaidic acid (ORT3vsT1= 1.52; 95% CI = 1.14-2.03; markedly both in premenopausal and in non-obese women), and high oleic to stearic acids ratio (ORT3vsT1= 2.04; 95% CI = 1.45-2.87) showed higher risk. These associations were similar in all BC pathological subtypes. Conclusions: Our results, which should be confirmed in future studies, emphasize the importance of analyzing fatty acids individually, as well as the desaturase activity indices. A decrease in the dietary intake of trans-monounsaturated fatty acids could be a good strategy for BC prevention.

Different spatial pattern of municipal prostate cancer mortality in younger men in Spain

Background

Prostate cancer (PC) primarily affects elderly men. However, the specific features of cases diagnosed at younger ages (<65 years) suggest that they may represent a different clinical subtype. Our aim was to assess this suggestion by contrasting the geographical PC mortality and hospital admissions patterns in Spain for all ages to those in younger men.

Methods

The Spanish National Institute of Statistics supplied data on PC mortality, hospital admission, and population data. We estimated the expected town-specific number of deaths and calculated the standardized mortality ratios. Spatial autoregressive models of Besag-York-Mollié provided smoother municipal estimators of PC mortality risk (all ages; <65 years). We computed the provincial age-standardized rate ratios of PC hospital admissions (all men; <60 years) using Spanish rates as the reference.

Results

A total of 29,566 PC deaths (6% among those <65 years) were registered between 2010–2014, with three high-mortality risk zones: Northwest Spain; Southwest Andalusia & Granada; and a broad band extending from the Pyrenees Mountains to the north of Valencia. In younger men, the spatial patterns shared the high risk of mortality in the Northwest but not the central band. The PC hospital discharge rates confirmed a North-South gradient but also low mortality/high admission rates in Madrid and Barcelona and the opposite in Southwest Andalusia.

Conclusion

The consistent high PC mortality/morbidity risk in the Northwest of Spain indicates an area with a real excess of risk. The different spatial pattern in younger men suggests that some factors associated with geographical risk might have differential effects by age. Finally, the regional divergences in mortality and morbidity hint at clinical variability as a source of inequity within Spain.

Impact of declining exposure to secondhand tobacco smoke in public places to decreasing smoking-related cancer mortality in the US population

BACKGROUND

The major decrease in exposure to secondhand smoke (SHS) in public places in recent decades could have contributed to the decline in smoking-related cancer mortality observed in the US population.

METHODS

Prospective study among 11,856 non-smoking adults aged ≥40 years who participated in NHANES 1988-1994 or 1999-2004 and were followed for mortality through 2006. We estimated the amount of change in cancer mortality over time attributed to the intermediate pathway of changes in SHS exposure in public places, after adjustment for risk factors and SHS exposure at home.

RESULTS

The adjusted smoking-related cancer mortality rate ratios (95% CI) for a two-fold increase in serum cotinine and a 1-hour increase in occupational SHS exposure time were 1.10 (1.03, 1.17) and 1.14 (1.06, 1.24) for all-cancer, and 1.13 (1.03, 1.24) and 1.14 (1.02, 1.26) for smoking-related cancer, respectively. The absolute reduction in mortality comparing 1999-2004 to 1988-1994 was 75.8 (-25.5, 177.0) and 77.0 (2.6, 151.4) deaths/100,000 person-years, for all-cancer and smoking-related cancer, respectively. Among these avoided all-cancer deaths, 45.8 (2.8, 89.5) and 18.1 (-1.2, 39.6)/100,000 person-year were attributable to changes in serum cotinine concentrations and occupational SHS exposure time, respectively. The corresponding numbers of smoking-related cancer avoided deaths were 36.4 (0.7, 72.8) and 9.9 (-3.8, 24.9)/100,000 person-year.

CONCLUSIONS

Declines in SHS exposure were associated with reductions in all-cancer and smoking-related cancer mortality, supporting that smoking bans in public places may have reduced cancer mortality among non-smoking adults.

Effect of mistimed eating patterns on breast and prostate cancer risk (MCC-Spain Study)

Modern life involves mistimed sleeping and eating patterns that in experimental studies are associated with adverse health effects. We assessed whether timing of meals is associated with breast and prostate cancer risk taking into account lifestyle and chronotype, a characteristic correlating with preference for morning or evening activity. We conducted a population‐based case‐control study in Spain, 2008–2013. In this analysis we included 621 cases of prostate and 1,205 of breast cancer and 872 male and 1,321 female population controls who had never worked night shift. Subjects were interviewed on timing of meals, sleep and chronotype and completed a Food Frequency Questionaire. Adherence to the World Cancer Research Fund/American Institute of Cancer Research recommendations for cancer prevention was examined. Compared with subjects sleeping immediately after supper, those sleeping two or more hours after supper had a 20% reduction in cancer risk for breast and prostate cancer combined (adjusted Odds Ratio [OR] = 0.80, 95%CI 0.67–0.96) and in each cancer individually (prostate cancer OR = 0.74, 0.55–0.99; breast cancer OR = 0.84, 0.67–1.06). A similar protection was observed in subjects having supper before 9 pm compared with supper after 10 pm. The effect of longer supper‐sleep interval was more pronounced among subjects adhering to cancer prevention recommendations (OR both cancers= 0.65, 0.44–0.97) and in morning types (OR both cancers = 0.66, 0.49–0.90). Adherence to diurnal eating patterns and specifically a long interval between last meal and sleep are associated with a lower cancer risk, stressing the importance of evaluating timing in studies on diet and cancer.

What's new?

Evidence shows that long‐term disruption of endogenous circadian rhythms may be associated with cancer. The effects of mistimed sleeping and eating patterns that come with modern life are however less clear. This large Spanish population‐based study examined whether meal timing and sleep patterns are associated with the two most common nightshift‐related cancers. Adherence to a more diurnal eating pattern, and specifically an early supper and a long interval between last meal and sleep were associated with a lower breast and prostate cancer risk, stressing the importance of evaluating circadian rhythms in diet and cancer studies and revisiting recommendations for prevention.

The RS4939827 polymorphism in the SMAD7 GENE and its association with Mediterranean diet in colorectal carcinogenesis

Background

The objective of our investigation is to study the relationship between the rs4939827 SNP in the SMAD7 gene, Mediterranean diet pattern and the risk of colorectal cancer.

Methods

We examined 1087 cases of colorectal cancer and 2409 population controls with available DNA samples from the MCC-Spain study, 2008–2012. Descriptive statistical analyses, and multivariate logistic mixed models were performed. The potential synergistic effect of rs4939827 and the Mediterranean diet pattern was evaluated with logistic regression in different strata of of adherence to the Mediterranean diet and the genotype.

Results

High adherence to Mediterrenean diet was statistically significantly associated with colorectal cancer risk. A decreased risk for CRC cancer was observed for the CC compared to the TT genotype (OR = 0.65 and 95% CI = 0.51–0.81) of the rs4939827 SNP Also, we could show an association between the Mediterranean diet pattern (protective factor) and rs4939827. Although the decreased risk for the CC genotype was slightly more pronounced in subjects with high adherence to Mediterrenean diet, there was no statistically significant synergistic effect between genotype CC and adherence to the Mediterranean dietary pattern factors.

Conclusion

The SMAD7 gene and specifically the allele C could be protective for colorectal cancer. An independent protective association was also observed between high adherence Mediterranean diet pattern and CRC risk. Findings form this study indicate that high adherence to Mediterranean diet pattern has a protective role for CRC cancer probably involving the Tumor Growth Factor- β pathway in this cancer.

Electronic supplementary material

The online version of this article (10.1186/s12881-017-0485-5) contains supplementary material, which is available to authorized users.

Mammographic density and ageing: A collaborative pooled analysis of cross-sectional data from 22 countries worldwide

BACKGROUND

Mammographic density (MD) is one of the strongest breast cancer risk factors. Its age-related characteristics have been studied in women in western countries, but whether these associations apply to women worldwide is not known.

METHODS AND FINDINGS

We examined cross-sectional differences in MD by age and menopausal status in over 11,000 breast-cancer-free women aged 35-85 years, from 40 ethnicity- and location-specific population groups across 22 countries in the International Consortium on Mammographic Density (ICMD). MD was read centrally using a quantitative method (Cumulus) and its square-root metrics were analysed using meta-analysis of group-level estimates and linear regression models of pooled data, adjusted for body mass index, reproductive factors, mammogram view, image type, and reader. In all, 4,534 women were premenopausal, and 6,481 postmenopausal, at the time of mammography. A large age-adjusted difference in percent MD (PD) between post- and premenopausal women was apparent (-0.46 cm [95% CI: -0.53, -0.39]) and appeared greater in women with lower breast cancer risk profiles; variation across population groups due to heterogeneity (I2) was 16.5%. Among premenopausal women, the √PD difference per 10-year increase in age was -0.24 cm (95% CI: -0.34, -0.14; I2 = 30%), reflecting a compositional change (lower dense area and higher non-dense area, with no difference in breast area). In postmenopausal women, the corresponding difference in √PD (-0.38 cm [95% CI: -0.44, -0.33]; I2 = 30%) was additionally driven by increasing breast area. The study is limited by different mammography systems and its cross-sectional rather than longitudinal nature.

CONCLUSIONS

Declines in MD with increasing age are present premenopausally, continue postmenopausally, and are most pronounced over the menopausal transition. These effects were highly consistent across diverse groups of women worldwide, suggesting that they result from an intrinsic biological, likely hormonal, mechanism common to women. If cumulative breast density is a key determinant of breast cancer risk, younger ages may be the more critical periods for lifestyle modifications aimed at breast density and breast cancer risk reduction.

Colorectal Cancer and Long-Term Exposure to Trihalomethanes in Drinking Water: A Multicenter Case-Control Study in Spain and Italy

BACKGROUND

Evidence on the association between colorectal cancer and exposure to disinfection by-products in drinking water is inconsistent.

OBJECTIVES

We assessed long-term exposure to trihalomethanes (THMs), the most prevalent group of chlorination by-products, to evaluate the association with colorectal cancer.

METHODS

A multicenter case-control study was conducted in Spain and Italy in 2008-2013. Hospital-based incident cases and population-based (Spain) and hospital-based (Italy) controls were interviewed to ascertain residential histories, type of water consumed in each residence, frequency and duration of showering/bathing, and major recognized risk factors for colorectal cancer. We estimated adjusted odds ratios (OR) for colorectal cancer in association with quartiles of estimated average lifetime THM concentrations in each participant's residential tap water (micrograms/liter; from age 18 to 2 years before the interview) and estimated average lifetime THM ingestion from drinking residential tap water (micrograms/day).

RESULTS

We analyzed 2,047 cases and 3,718 controls. Median values (ranges) for average lifetime residential tap water concentrations of total THMs, chloroform, and brominated THMs were 30 (0-174), 17 (0-63), and 9 (0-145) μg/L, respectively. Total THM concentration in residential tap water was not associated with colorectal cancer (OR = 0.92, 95% CI: 0.66, 1.28 for highest vs. lowest quartile), but chloroform concentrations were inversely associated (OR = 0.31, 95% CI: 0.24, 0.41 for highest vs. lowest quartile). Brominated THM concentrations showed a positive association among men in the highest versus the lowest quartile (OR = 1.43, 95% CI: 0.83, 2.46). Patterns of association were similar for estimated average THM ingestion through residential water consumption.

CONCLUSIONS

We did not find clear evidence of an association between detailed estimates of lifetime total THM exposure and colorectal cancer in our large case-control study population. Negative associations with chloroform concentrations and ingestion suggest differences among specific THMs, but these findings should be confirmed in other study populations. Citation: Villanueva CM, Gracia-Lavedan E, Bosetti C, Righi E, Molina AJ, Martín V, Boldo E, Aragonés N, Perez-Gomez B, Pollan M, Gomez Acebo I, Altzibar JM, Jiménez Zabala A, Ardanaz E, Peiró R, Tardón A, Chirlaque MD, Tavani A, Polesel J, Serraino D, Pisa F, Castaño-Vinyals G, Espinosa A, Espejo-Herrera N, Palau M, Moreno V, La Vecchia C, Aggazzotti G, Nieuwenhuijsen MJ, Kogevinas M. 2017. Colorectal cancer and long-term exposure to trihalomethanes in drinking water: a multicenter case---control study in Spain and Italy. Environ Health Perspect 125:56-65; http://dx.doi.org/10.1289/EHP155.

Ingested Nitrate and Breast Cancer in the Spanish Multicase-Control Study on Cancer (MCC-Spain)

BACKGROUND

Ingested nitrate leads to endogenous formation of N-nitroso compounds that are breast carcinogens in animals, but human evidence is limited.

OBJECTIVE

We evaluated ingested nitrate as a risk factor for breast cancer (BC) in a multicase-control study.

METHODS

Hospital-based incident BC cases and population-based controls were recruited in eight Spanish regions in 2008-2013; participants provided residential and water consumption from 18 years of age and information on known BC risk factors. Long-term nitrate levels (1940-2010) were estimated and linked with residential histories and water consumption to calculate waterborne ingested nitrate (milligrams/day). Dietary ingested nitrate (milligrams/day) was calculated using food frequency questionnaires and published dietary nitrate contents. Interactions with endogenous nitrosation factors and other variables were evaluated. A total of 1,245 cases and 1,520 controls were included in the statistical analysis.

RESULTS

Among the study regions, average ± SD waterborne ingested nitrate ranged from 2.9 ± 1.9 to 13.5 ± 7.5 mg/day, and dietary ingested nitrate ranged from 88.5 ± 48.7 to 154 ± 87.8 mg/day. Waterborne ingested nitrate was not associated with BC overall, but among postmenopausal women, those with both high nitrate (> 6 vs. < 2.6 mg/day) and high red meat intake (≥ 20 vs. < 20 g/day) were more likely to be cases than women with low nitrate and low red meat intake (adjusted odds ratio = 1.64; 95% confidence interval: 1.08, 2.49; overall interaction p-value = 0.17). No association was found with dietary nitrate.

CONCLUSIONS

Waterborne ingested nitrate was associated with BC only among postmenopausal women with high red meat consumption. Dietary nitrate was not associated with BC regardless of the animal or vegetable source or of menopausal status.

CITATION

Espejo-Herrera N, Gracia-Lavedan E, Pollan M, Aragonés N, Boldo E, Perez-Gomez B, Altzibar JM, Amiano P, Zabala AJ, Ardanaz E, Guevara M, Molina AJ, Barrio JP, Gómez-Acebo I, Tardón A, Peiró R, Chirlaque MD, Palau M, Muñoz M, Font-Ribera L, Castaño-Vinyals G, Kogevinas M, Villanueva CM. 2016. Ingested nitrate and breast cancer in the Spanish Multicase-Control Study on Cancer (MCC-Spain). Environ Health Perspect 124:1042-1049; http://dx.doi.org/10.1289/ehp.1510334.

Healthcare coverage for undocumented migrants in Spain: Regional differences after Royal Decree Law 16/2012

The economic crisis has prompted the debate on how to regulate health coverage of undocumented migrants in publicly funded healthcare systems. Spain, as one of the most heavily affected countries in Europe, can be considered a case of particular interest. In 2012 the Spanish Government issued a Royal Decree Law (RDL 16/2012) which revoked their previous full right to public healthcare coverage, now limited for some exceptions. However, the Spanish National Health System is highly decentralized, and this Central Government decree had to be implemented by the Regional Health Authorities. Our aim is to compare regional policies regarding entitlement to healthcare for undocumented migrants after RDL 16/2012 in the 17 Autonomous Regions by performing an exhaustive review of the regional health policy regulations published after the enactment of RDL 16/2012. Our analysis shows that many Regions adopted legal, legislative and administrative actions to void or limit its effects, while others applied it as intended, resulting in huge differences in healthcare coverage for irregular migrants among Spanish Regions. The unequal implementation of this Law constitutes a paradigmatic example of the complexity of nation-wide regulation of controversial key issues in decentralized health systems. In addition, our results highlight that within-country differences in access and/or entitlement can be as relevant as those reported among-country when there is healthcare decentralization.

International Consortium on Mammographic Density: Methodology and population diversity captured across 22 countries

Mammographic density (MD) is a quantitative trait, measurable in all women, and is among the strongest markers of breast cancer risk. The population-based epidemiology of MD has revealed genetic, lifestyle and societal/environmental determinants, but studies have largely been conducted in women with similar westernized lifestyles living in countries with high breast cancer incidence rates. To benefit from the heterogeneity in risk factors and their combinations worldwide, we created an International Consortium on Mammographic Density (ICMD) to pool individual-level epidemiological and MD data from general population studies worldwide. ICMD aims to characterize determinants of MD more precisely, and to evaluate whether they are consistent across populations worldwide. We included 11755 women, from 27 studies in 22 countries, on whom individual-level risk factor data were pooled and original mammographic images were re-read for ICMD to obtain standardized comparable MD data. In the present article, we present (i) the rationale for this consortium; (ii) characteristics of the studies and women included; and (iii) study methodology to obtain comparable MD data from original re-read films. We also highlight the risk factor heterogeneity captured by such an effort and, thus, the unique insight the pooled study promises to offer through wider exposure ranges, different confounding structures and enhanced power for sub-group analyses.

Levels and predictors of persistent organic pollutants in an adult population from four Spanish regions

This research aimed to assess serum concentrations of a group of persistent organic pollutants (POPs) in a sample of adults recruited in four different regions from Spain and to assess socio-demographic, dietary, and lifestyle predictors of the exposure. The study population comprised 312 healthy adults selected from among controls recruited in the MCC-Spain multicase-control study. Study variables were collected using standardized questionnaires, and pollutants were analyzed by means of gas chromatography with electron capture detection. Multivariable analyses were performed to identify predictors of log-transformed pollutant concentrations, using combined backward and forward stepwise multiple linear regression models. Detection rates ranged from 89.1% (hexachlorobenzene, HCB) to 93.6% (Polychlorinated biphenyl-153 [PCB-153]); p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) showed the highest median concentrations (1.04ng/ml), while HCB showed the lowest (0.24ng/ml). In the multivariable models, age was positively associated with HCB, p,p'-DDE, and PCB-180. BMI was associated positively with p,p'-DDE but negatively with PCB-138. Total accumulated time residing in an urban area was positively associated with PCB-153 concentrations. The women showed higher HCB and lower p,p'-DDE concentrations versus the men. Notably, POP exposure in our study population was inversely associated with the breastfeeding received by participants and with the number of pregnancies of their mothers but was not related to the participants' history of breastfeeding their children or parity. Smoking was negatively associated with HCB and PCB-153 concentrations. Consumption of fatty foods, including blue fish, was in general positively associated with POP levels. Although POP environmental levels are declining worldwide, there is a need for the continuous monitoring of human exposure in the general population. The results of the present study confirm previous findings and point to novel predictors of long-term exposure to persistent organic pollutants.

Mercury, cadmium, and lead levels in human placenta: a systematic review

BACKGROUND

Placental tissue may furnish information on the exposure of both mother and fetus. Mercury (Hg), cadmium (Cd), and lead (Pb) are toxicants of interest in pregnancy because they are associated with alterations in child development.

OBJECTIVES

The aim of this study was to summarize the available information regarding total Hg, Cd, and Pb levels in human placenta and possible related factors.

METHODS

We performed a systematic search of PubMed/MEDLINE, EMBASE, Lilacs, OSH, and Web of Science for original papers on total Hg, Cd, or Pb levels in human placenta that were published in English or Spanish (1976-2011). Data on study design, population characteristics, collection and analysis of placenta specimens, and main results were extracted using a standardized form.

RESULTS

We found a total of 79 papers (73 different studies). Hg, Cd, and Pb levels were reported in 24, 46, and 46 studies, respectively. Most studies included small convenience samples of healthy pregnant women. Studies were heterogeneous regarding populations selected, processing of specimens, and presentation of results. Hg concentrations > 50 ng/g were found in China (Shanghai), Japan, and the Faroe Islands. Cd levels ranged from 1.2 ng/g to 53 ng/g and were highest in the United States, Japan, and Eastern Europe. Pb showed the greatest variability, with levels ranging from 1.18 ng/g in China (Shanghai) to 500 ng/g in a polluted area of Poland.

CONCLUSION

The use of the placenta as a biomarker to assess heavy metals exposure is not properly developed because of heterogeneity among the studies. International standardized protocols are needed to enhance comparability and increase the usefulness of this promising tissue in biomonitoring studies.

Municipal distribution of bladder cancer mortality in Spain: possible role of mining and industry

Background

Spain shows the highest bladder cancer incidence rates in men among European countries. The most important risk factors are tobacco smoking and occupational exposure to a range of different chemical substances, such as aromatic amines.

Methods

This paper describes the municipal distribution of bladder cancer mortality and attempts to "adjust" this spatial pattern for the prevalence of smokers, using the autoregressive spatial model proposed by Besag, York and Molliè, with relative risk of lung cancer mortality as a surrogate.

Results

It has been possible to compile and ascertain the posterior distribution of relative risk for bladder cancer adjusted for lung cancer mortality, on the basis of a single Bayesian spatial model covering all of Spain's 8077 towns. Maps were plotted depicting smoothed relative risk (RR) estimates, and the distribution of the posterior probability of RR>1 by sex. Towns that registered the highest relative risks for both sexes were mostly located in the Provinces of Cadiz, Seville, Huelva, Barcelona and Almería. The highest-risk area in Barcelona Province corresponded to very specific municipal areas in the Bages district, e.g., Suría, Sallent, Balsareny, Manresa and Cardona.

Conclusion

Mining/industrial pollution and the risk entailed in certain occupational exposures could in part be dictating the pattern of municipal bladder cancer mortality in Spain. Population exposure to arsenic is a matter that calls for attention. It would be of great interest if the relationship between the chemical quality of drinking water and the frequency of bladder cancer could be studied.

Cutaneous melanoma: hints from occupational risks by anatomic site in Swedish men

AIMS

To improve knowledge of the epidemiology of melanoma by comparing occupational risks of cutaneous melanoma (CM) by anatomic site in Swedish workers.

METHODS

Male workers employed in 1970 and living in the country in 1960 were followed up from 1971 to 1989 using the Swedish Registers of Death and Cancer. A more specifically exposed subcohort included men reporting the same occupation in 1960 and 1970. For each location, occupational risk ratios (RRs) were extracted from Poisson regression models adjusted by age, period, town size, and geographical area. To diminish the influence of socioeconomic factors, intrasector analyses, comparing only jobs belonging to the same occupational sector, were performed. Risk patterns for different locations were compared.

RESULTS

High RRs for different sites were found among workers exposed to UV sources (dentists, physiotherapists, and lithographers), and sun exposed workers (harbour masters, and lighthouse/related work). Risk excesses were seen in fur tailors, tanners/fur dressers, patternmakers/cutters, electrical fitters/wiremen, telephone/telegraph installers/repairmen, and some glass/pottery/tile workers. Results for lower and upper limbs were significantly correlated but somewhat independent of those found in thorax, the most frequent location. Correlation between head/neck and thorax was moderate. Specific risk excesses were found for rolling mill workers in head/neck, for chimney sweeps in upper limbs, and for aircraft pilots/navigators/flight engineers in lower limbs.

CONCLUSIONS

High RRs in the trunk among occupations with UV exposure from artificial sources suggest an effect not restricted to exposed sites. An unusual distribution of cases and RRs in chimney sweeps, rolling-mill, or glass/pottery/tile workers suggests local effects of exposures. The not previously reported risk excess in this job and in fur related processes, and the RR in electrical fitters and telephone/telegraph installers deserve further investigation. Disparities between locations, as RRs in thorax and limbs, may reflect differences in aetiological mechanisms.