Breast cancer risk for the joint exposure to metals and metalloids in women: Results from the EPIC-Spain cohort

Environmental factors play a role in breast cancer development. While metals and metalloids (MMs) include some carcinogens, their association with breast cancer depends on the element studied. Most studies focus on individual MMs, but the combined effects of metal mixtures remain unclear. The aim of this study was to analyze the relationship between the joint exposure to MMs and the risk of developing female breast cancer. We conducted a case-control study within the multicenter prospective EPIC-Spain cohort. Study population comprised 292 incident cases and 286 controls. Plasma concentrations of 16 MMs were quantified at recruitment. Potential confounders were collected using a questionnaire and anthropometric measurements. Mixed-effects logistic regression models were built to explore the effect of individual MMs. Quantile-based g computation models were applied to identify the main mixture components and to estimate the joint effect of the metal mixture. The geometric means were highest for Cu (845.6 ng/ml) and Zn (604.8 ng/ml). Cases had significantly higher Cu concentrations (p = 0.010) and significantly lower Zn concentrations (p < 0.001). Cu (+0.42) and Mn (+0.13) showed the highest positive weights, whereas Zn (-0.61) and W (-0.16) showed the highest negative weights. The joint effect of the metal mixture was estimated at an OR = 4.51 (95%CI = 2.32-8.79), suggesting a dose-response relationship. No evidence of non-linearity or non-additivity was found. An unfavorable exposure profile, primarily characterized by high Cu and low Zn levels, could lead to a significant increase in the risk of developing female breast cancer. Further studies are warranted to confirm these findings.

Blood Selenium Concentrations Are Inversely Associated with the Risk of Undernutrition in Older Adults

BACKGROUND

Selenium is an essential trace element with an antioxidant and anti-inflammatory capacity that has been associated in experimental studies with beneficial effects on appetite control, the regulation of the gut microbiota, and control of the anabolic-catabolic balance. The main aim of the present study was to evaluate the association between circulating selenium concentrations and the risk of developing undernutrition in older adults.

METHODS

This was a cohort study with 1398 well-nourished community-dwelling individuals aged ≥ 65 years residing in Spain in 2017, who were followed for a mean of 2.3 years. Whole blood selenium was measured at baseline using inductively coupled plasma-mass spectrometry. Undernutrition was assessed at baseline and at follow-up, and defined as having at least one of the three GLIM phenotypic criteria (involuntary weight loss, a low body mass index, and a reduced muscle mass) and at least one of the two etiologic criteria (reduced food consumption or nutrient assimilation and inflammation/disease burden).

RESULTS

During the follow-up, 142 participants (11%) developed moderate undernutrition and 113 (8.8%) severe undernutrition. The standardized relative risks of moderate and severe undernutrition at the 75th percentile of Se levels versus the 25th were 0.90 and 0.70, respectively. In dose-response analyses, the risk of severe undernutrition decreased linearly with increasing selenium concentrations. This association was independent of protein intake or diet quality and was stronger among participants with a diagnosis of a musculoskeletal disorder.

CONCLUSIONS

The results suggest that an adequate dietary selenium status is needed to prevent undernutrition in older adults. Also, this may open the door for clinical trials with selenium supplementation, at doses considered as safe, to prevent undernutrition.

Association between serum copper levels and risk of cardiovascular disease: A nested case-control study in the PREDIMED trial

BACKGROUND AND AIM

Certain trace elements have been associated with increased cardiovascular risk. The aim of this study was to evaluate the association between serum copper (S-Cu) levels and the risk of a first event of cardiovascular disease (CVD) in a population of older adults with high cardiovascular risk.

METHODS AND RESULTS

We conducted a case-control study nested within the PREDIMED trial. During a median follow-up of 4.8 years, a total of 207 incident cases diagnosed with CVD were matched for sex, age, and intervention group with 436 controls. Personal interviews, reviews of medical records, and validated questionnaires were used to assess known CVD risk factors. Biological serum samples were collected annually. Inductively coupled plasma mass spectrometry analysis was used to determine S-Cu levels. Adjusted odds ratios were calculated using multivariate conditional logistic regression models. All participants had S-Cu levels within the reference values, 750 μg/L to 1450 μg/L. Among men, but not among women, the mean S-Cu concentration was higher in cases 1014.1 μg/L than in controls 959.3 μg/L; (p = 0.004). In men, the multivariable-adjusted odds ratio for CVD was 2.36 (95% CI 1.07-5.20 for the comparison of the highest vs. the lowest quartile; p for trend = 0.02), in women, it was 0.43 (95% CI 0.11-1.70; p for trend = 0.165).

CONCLUSION

In older Spanish men with high cardiovascular risk, a significant association was observed between high S-Cu levels, but still within the reference values, and an increased risk of a first event of CVD. Our findings suggest a sex difference in CVD risk and S-Cu levels. To confirm this relationship and to analyze the differences observed between men and women, further studies are needed.

Association of genetic polymorphisms in detoxifying systems and urinary metal(loid) levels with excess body weight among Spanish children: A proof-of-concept study

Exposure to metal(loid)s during critical developmental windows could result in permanent damage to the target organ system, increasing susceptibility to disease later in life. In view of the fact that metals(loid)s have been shown to work as obesogens, the aim of the present case-control study was to evaluate the modification effect of exposure to metal(loid)s on the association between SNPs in genes involved in metal(loid) detoxification and excess body weight among children. A total of 134 Spanish children aged 6-12 years old were included (88 controls and 46 cases). Seven SNPs (GSTP1 rs1695 and rs1138272; GCLM rs3789453, ATP7B rs1061472, rs732774 and rs1801243; and ABCC2 rs1885301) were genotyped on GSA microchips, and ten metal(loid)s were analysed in urine samples through Inductively coupled plasma mass spectrometry (ICP-MS). Multivariable logistic regressions were conducted to assess the genetic and metal exposures' main association and interaction effects. GSTP1 rs1695 and ATP7B rs1061472 showed significant effects on excess weight increase in those children carrying two copies of the risk G allele and being highly exposed to chromium (ORa = 5.38, p = 0.042, p interaction = 0.028 for rs1695; and ORa = 4.20, p = 0.035, p interaction = 0.012 for rs1061472) and lead (ORa = 7.18, p = 0.027, p interaction = 0.031 for rs1695, and ORa = 3.42, p = 0.062, p interaction = 0.010 for rs1061472). Conversely, GCLM rs3789453 and ATP7B rs1801243 appeared to play a protective role against excess weight in those exposed to copper (ORa = 0.20, p = 0.025, p interaction = 0.074 for rs3789453) and lead (ORa = 0.22, p = 0.092, p interaction = 0.089 for rs1801243). Our findings provide the first proof that interaction effects could exist between genetic variants within GSH and metal transporting systems and exposure to metal(loid)s, on excess body weight among Spanish children.

Kisspeptin as potential biomarker of environmental chemical mixture effect on reproductive hormone profile: A pilot study in adolescent males

BACKGROUND

Kisspeptin has been proposed as an effect biomarker to understand the mechanisms by which some environmental chemicals adversely affect the human reproductive system.

OBJECTIVE

To ascertain whether kisspeptin serum protein and DNA methylation levels are associated with exposure to several environmental chemicals (individually and as a mixture) and serum reproductive hormone levels in adolescent males.

METHODS

Three phenols (bisphenol A [BPA], methyl-paraben [MPB], and benzophenone-3 [BP3]); two toxic metals (arsenic and cadmium); and four metabolites of non-persistent pesticides, including insecticides (2-isopropyl-6-methyl-4-pyrimidinol [IMPy], malathion diacid [MDA], and dimethylcyclopropane carboxylic acid [DCCA]) and fungicides (ethylene thiourea [ETU]) were measured in first-morning urine samples of 133 adolescent males aged 15-17 years from the INMA-Granada cohort. In blood samples collected on the same day, KISS1 gene DNA methylation was measured at four CpGs from the Exon IV, as well as serum levels of kiss54 protein, total testosterone (T), estradiol (E₂), sex hormone binding-globulin, dehydroepiandrosterone sulfate, luteinizing hormone (LH), and follicle-stimulating hormone (FSH). Multiple linear regression and mixture (quantile g-computation) models were fit.

RESULTS

Urinary MDA and DCCA concentrations were associated with higher kiss54 levels [% change (95%CI) for each log-unit increase in concentration = 2.90 (0.32;5.56), and 1.93 (0.45,3.43), respectively]; IMPy with lower DNA methylation percentage at CpG1 and total CpGs [% change (95%CI) = -1.15 (-1.96;-0.33): -0.89 (-1.73;-0.01), respectively]; and BP3 and DCCA with lower total CpGs methylation [-0.53 (-1.04;-0.01) and - 0.69 (-1.37;-0.01), respectively]. The pesticide mixture and the whole chemical mixture were associated with higher kiss54 [% change (95%CI) = 9.09 (3.29;15.21) and 11.61 (3.96;19.82), respectively] and lower methylation levels at several CpGs. Additionally, serum kiss54 in the third tertile was associated with higher LH levels [% change (95%CI) = 28.69 (3.75-59.63)], and third-tertile CpG1, CpG2, and total CpG methylation percentages were associated with lower FSH and E₂.

CONCLUSION

The findings of the present study and the negative correlation between serum kiss54 levels and KISS1 DNA methylation percentages suggested that kisspeptin may be a promising effect biomarker.

Concentrations and predictors of aluminum, antimony, and lithium in breast milk: A repeated-measures study of donors

Aluminum (Al), antimony (Sb), and lithium (Li) are relatively common toxic metal(oid)s that can be transferred into breast milk and potentially to the nursing infant. This study assessed concentrations of Al, Sb, and Li in breast milk samples collected from donor mothers and explored the predictors of these concentrations. Two hundred forty-two pooled breast milk samples were collected at different times post-partum from 83 donors in Spain (2015-2018) and analyzed for Al, Sb, and Li concentrations. Mixed-effect linear regression was used to investigate the association of breast milk concentrations of these elements with the sociodemographic profile of the women, their dietary habits and utilization of personal care products (PCPs), the post-partum interval, and the nutritional characteristics of milk samples, among other factors. Al was detected in 94% of samples, with a median concentration of 57.63 μg/L. Sb and Li were detected in 72% and 79% of samples at median concentrations of 0.08 μg/L and 0.58 μg/L, respectively. Concentrations of Al, Sb, and Li were not associated with post-partum time. Al was positively associated with total lipid content of samples, weight change since before pregnancy, and coffee and butter intakes and inversely with meat intake. Li was positively associated with intake of chocolate and use of face cream and eyeliner and inversely with year of sample collection, egg, bread, and pasta intakes, and use of hand cream. Sb was positively associated with fatty fish, yoghurt, rice, and deep-fried food intakes and use of eyeliner and inversely with egg and cereal intakes and use of eyeshadow. This study shows that Al, Sb, and Li, especially Al, are widely present in donor breast milk samples. Their concentrations in the milk samples were most frequently associated with dietary habits but also with the lipid content of samples and the use of certain PCPs.

Passive exposure to electronic cigarette aerosol in pregnancy: A case study of a family

BACKGROUND

Passive exposure to the aerosols of electronic cigarettes (e-cigarettes) has been little studied. We assessed this exposure in late pregnancy in a woman and her 3-year-old child, exposed through e-cigarette use by another household member.

METHODS

This prospective longitudinal case study involved a family unit consisting of an e-cigarette user, a pregnant woman who delivered an infant during the study, and the couple's older 3-year-old son. At 31, 36, and 40 weeks of the pregnancy, we measured biomarkers (nicotine metabolites, tobacco-specific nitrosamines, propanediols, glycerol, and metals) in the urine and hair of all three participants and in the saliva of the adults, in cord blood at delivery, and in the breast milk at the postpartum period.

RESULTS

Samples from the e-cigarette user showed quantifiable concentrations of all analytes assessed (maximum urinary cotinine concentration, 4.9 ng/mL). Among samples taken from the mother, nicotine and its metabolites were found mainly in urine and also in saliva and hair, but not in cord blood. During the postpartum period, we found cotinine concentrations of 2.2 ng/mL in the mother's urine and 0.22 ng/mL in breast milk; 1,2-propanediol was generally detected in urine and saliva, but not in cord blood or breast milk. The maximum urinary cotinine concentration in the 3-year-old child was 2.6 ng/mL and propanediols also were detected in his urine. Nitrosamines were not detected in samples taken from the mother or the 3-year-old. Metals found in the refill liquid were detected at low levels in both the mother and the 3-year-old.

CONCLUSIONS

We detected low but not negligible concentrations of e-cigarette-related analytes (including cord blood and breast milk) in an exposed pregnant non-user and in a 3-year-old child also living in the home. Passive exposure to e-cigarette aerosols cannot be disregarded and should be assessed in larger observational studies.

Exposure to secondhand aerosol from electronic cigarettes at homes: A real-life study in four European countries

Electronic cigarette (e-cigarette) use emits potentially hazardous compounds and deteriorates indoor air quality. Home is a place where e-cigarettes may frequently be used amid its increasing prohibition in public places. This study assessed the real-life scenario of bystanders' exposure to secondhand e-cigarette aerosol (SHA) at home. A one-week observational study was conducted within the TackSHS project in four countries (Greece, Italy, Spain, and the United Kingdom) in 2019 including: 1) homes of e-cigarette users living together with a non-user/non-smoker; and 2) control homes with no smokers nor e-cigarette users. Indoor airborne nicotine, PM2.5, and PM1.0 concentrations were measured as environmental markers of SHA. Biomarkers, including nicotine and its metabolites, tobacco-specific nitrosamines, propanediol, glycerol, and metals were measured in participants' saliva and urine samples. E-cigarette use characteristics, such as e-cigarette refill liquid's nicotine concentration, e-cigarette type, place of e-cigarette use at home, and frequency of ventilation, were also collected. A total of 29 e-cigarette users' homes and 21 control homes were included. The results showed that the seven-day concentrations of airborne nicotine were quantifiable in 21 (72.4 %) out of 29 e-cigarette users' homes; overall, they were quite low (geometric mean: 0.01 μg/m3; 95 % CI: 0.01-0.02 μg/m3) and were all below the limit of quantification in control homes. Seven-day concentrations of PM2.5 and PM1.0 in e-cigarette and control homes were similar. Airborne nicotine and PM concentrations did not differ according to different e-cigarette use characteristics. Non-users residing with e-cigarette users had low but significantly higher levels of cotinine, 3'-OH-cotinine and 1,2-propanediol in saliva, and cobalt in urine than non-users living in control homes. In conclusion, e-cigarette use at home created bystanders' exposure to SHA regardless of the e-cigarette use characteristics. Further studies are warranted to assess the implications of SHA exposure for smoke-free policy.

Serum Selenium and Incident Cardiovascular Disease in the PREvención con DIeta MEDiterránea (PREDIMED) Trial: Nested Case-Control Study

Background: Selenium is an essential trace mineral with potential interest for cardiovascular disease (CVD) prevention owing to its antioxidant properties. Epidemiological data on selenium status and CVD remain inconsistent. The objective of this study was to ascertain whether low serum selenium (SSe) concentrations are related to an increased risk of a first CVD event in a population at high cardiovascular risk. Methods: We undertook a case-control study nested within the “PREvención con DIeta MEDiterránea” (PREDIMED) trial. A total of 207 participants diagnosed with CVD (myocardial infarction, stroke, or cardiovascular death) during the follow-up period (2003−2010) were matched by sex, age, and intervention group to 436 controls by incidence density sampling. Median time between serum sample collection and subsequent CVD event occurrence was 0.94 years. SSe levels were determined using inductively coupled plasma mass spectrometry analysis. Covariates were assessed through validated questionnaires, in-person interviews, and medical record reviews. Conditional logistic regression was used to calculate multivariable-adjusted odds ratios (ORs). Results: Among women, the mean SSe concentration was lower in cases than in controls (98.5 μg/L vs. 103.8 μg/L; p = 0.016). In controls, SSe levels were directly associated with percentage of total energy intake from proteins and fish intake (p for linear trend < 0.001 and 0.049, respectively), whereas SSe concentrations were inversely associated with age, body mass index, and percentage of total energy intake from carbohydrates (p for linear trend < 0.001, 0.008 and 0.016 respectively). In the total group, we observed an inverse dose−response gradient between SSe levels and risk of CVD in the fully-adjusted model (highest vs. lowest quartile: OR = 0.47, 95% CI: 0.27−0.81; ptrend = 0.003). Conclusions: Among elderly individuals at high cardiovascular risk, high SSe concentrations within population reference values are associated with lower first CVD incidence.

Cadmium exposure and growth differentiation factor-15 (GDF-15) levels in non-smoking older adults

BACKGROUND

Cadmium (Cd) exposure is a risk factor for cardiovascular disease (CVD); however, understanding the effects of Cd at the cellular level remains incomplete. Since growth differentiation factor-15 (GDF-15) is a cytokine produced in many cell types in response to tissue injury and inflammation that may capture several pathways between Cd and CVD, this study examined the relationship between blood Cd levels and serum GDF-15 concentrations in community-dwelling older adults.

METHODS

Cd and GDF-15 were measured in 1942 non-smoking individuals aged 65+ with no previous history of CVD. The association of Cd with GDF-15 was evaluated in linear regression models that adjusted for sociodemographic, lifestyle and biological risk factors, inflammatory biomarkers (IL-6, C-reactive protein and neutrophil to lymphocyte ratio), and markers of vascular damage (NTproBNP and cTnT-hs).

RESULTS

Geometric mean Cd exposure was 0.11 μg/L (0.09 in never- and 0.15 in former-smokers) and geometric mean GDF-15 was 1186.21 pg/mL (1182.67 in never- and 1191.66 in former-smokers). In multivariable analyses, we found a dose-response association between Cd levels and GDF-15: adjusted mean percentage differences in GDF-15 (95% confidence interval) per 2-fold increase in Cd concentrations in the overall non-smoking population and in never smokers were, respectively, 2.54% (1.01, 4.06) and 2.50% (0.47, 4.54). In spline regression, the dose-response relationship was progressive over the range of Cd concentrations with no significant departures from linearity.

CONCLUSIONS

Cd exposure may be related to enhanced GDF-15 expression. Future studies with repeated GDF-15 measurements should confirm the present findings to better understand the biological mechanisms underlying this association.

Effects of e-liquid flavor, nicotine content, and puff duration on metal emissions from electronic cigarettes

Vaping is the action of inhaling and exhaling aerosols from electronic cigarettes. The aerosols contain various amounts of toxic chemicals, including metals. The purpose of this study was to evaluate factors that can influence metal levels, including flavor and nicotine content in the e-liquid, and puff duration. Aerosols were collected from both closed-system (cartridge-based) and open-system e-cigarettes using e-liquids with different flavors (fruit, tobacco, and menthol), nicotine content (0, 6, 24, and 59 mg/mL), and different puff durations (1, 2, and 4 s). The concentrations of 14 metals in the collected aerosols were measured using inductively coupled plasma mass spectroscopy. Aerosol concentrations of As, Fe, and Mn varied significantly among fruit, tobacco, and menthol flavors in both closed-system and open-system devices. Concentrations of Al, Fe, Sn, and U were significantly higher in tobacco or menthol flavored aerosols compared to fruit flavors in closed-system devices. Aerosol W levels were significantly higher in tobacco flavored aerosols compared to fruit flavors in open-system devices. Concentrations of As, Fe, and Mn were higher in tobacco flavored aerosols compared to menthol flavors in both types of devices. The median Pb concentration decreased significantly from 15.8 to 0.88 μg/kg when nicotine content increased from 0 to 59 mg/mL, and median Ni concentration was 9.60 times higher in aerosols with nicotine of 59 mg/mL compared to 24 mg/mL (11.9 vs. 1.24 μg/kg) for closed-system devices. No significant differences were observed in aerosol metal concentrations for different puff durations. Aerosol metal concentrations varied widely between different flavors and nicotine content but not by puff duration. Flavor and nicotine content of the e-liquid could be potential factors in metal emissions. Some elements showed higher concentrations under certain conditions, highlighting the urgent need of developing strict product regulations, especially on e-liquid composition and nicotine content to inform e-cigarette users about metal exposure through vaping.

Healthy lifestyle, metabolomics and incident type 2 diabetes in a population-based cohort from Spain

Background

The contribution of metabolomic factors to the association of healthy lifestyle with type 2 diabetes risk is unknown. We assessed the association of a composite measure of lifestyle with plasma metabolite profiles and incident type 2 diabetes, and whether relevant metabolites can explain the prospective association between healthy lifestyle and incident type 2 diabetes.

Methods

A Healthy Lifestyle Score (HLS) (5-point scale including diet, physical activity, smoking status, alcohol consumption and BMI) was estimated in 1016 Hortega Study participants, who had targeted plasma metabolomic determinations at baseline examination in 2001–2003, and were followed-up to 2015 to ascertain incident type 2 diabetes.

Results

The HLS was cross-sectionally associated with 32 (out of 49) plasma metabolites (2.5% false discovery rate). In the subset of 830 participants without prevalent type 2 diabetes, the rate ratio (RR) and rate difference (RD) of incident type 2 diabetes (n cases = 51) per one-point increase in HLS was, respectively, 0.69 (95% CI, 0.51, 0.93), and − 8.23 (95% CI, − 16.34, − 0.13)/10,000 person-years. In single-metabolite models, most of the HLS-related metabolites were prospectively associated with incident type 2 diabetes. In probit Bayesian Kernel Machine Regression, these prospective associations were mostly driven by medium HDL particle concentration and phenylpropionate, followed by small LDL particle concentration, which jointly accounted for ~ 50% of the HLS-related decrease in incident type 2 diabetes.

Conclusions

The HLS showed a strong inverse association with incident type 2 diabetes, which was largely explained by plasma metabolites measured years before the clinical diagnosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-021-01219-3.

Exposure to metals and metalloids among pregnant women from Spain: Levels and associated factors

BACKGROUND

Humans are regularly exposed to metals and metalloids present in air, water, food, soil and domestic materials. Most of them can cross the placental barrier and cause adverse impacts on the developing foetus.

OBJECTIVES

To describe the prenatal concentrations of metals and metalloids and to study the associated sociodemographic, environmental and dietary factors in pregnant Spanish women.

METHODS

Subjects were 1346 pregnant women of the INMA Project, for whom the following metals arsenic (As), cadmium (Cd), cobalt (Co), copper (Cu), molybdenum (Mo), nickel (Ni), lead (Pb), antimony (Sb), selenium (Se), thallium (Tl) and zinc (Zn) were determined in urine, at both the first and the third trimesters of gestation. Sociodemographic, dietary and environmental information was collected through questionnaires during pregnancy. Multiple linear mixed models were built in order to study the association between each metal and metalloid concentrations and the sociodemographic, environmental and dietary factors.

RESULTS

The most detected compounds were As, Co, Mo, Sb, Se and Zn at both trimesters. Zn was the element found in the highest concentrations at both trimesters and Tl was detected in the lowest concentrations. We observed significant associations between As, Cd, Cu, Sb, Tl and Zn concentrations and working situation, social class and age. Seafood, meat, fruits, nuts, vegetables and alcohol intake affected the levels of all the metals but Cd and Cu. Proximity to industrial areas, fields and air pollution were related to all metals except Cd, Sb and Se.

CONCLUSIONS

This is the first large prospective longitudinal study on the exposure to metals and metalloids during pregnancy and associated factors to include several cohorts in Spain. The present study shows that some modifiable lifestyles, food intakes and environmental factors could be associated with prenatal exposure to metal(loid)s, which may be considered in further studies to assess their relationship with neonatal health outcomes.

Metal exposure and biomarker levels among e-cigarette users in Spain

The use of electronic cigarettes (e-cigarettes) has increased due to the belief that they are healthier than tobacco cigarettes. E-cigarettes contain a metallic heating coil (composed of Ni, Cr, Al and other metals) to heat a solution (commonly called e-liquid) and convert it into an aerosol. This aerosol is inhaled (vaped) by the users who can be potentially exposed to a wide variety of metals. We investigated the possible transfer of metals from the coil to the e-liquid and the generated aerosol, and how the exposure to this aerosol can increase metal body burden in e-cigarette users. We recruited 75 e-cigarette users (50 who only vaped and 25 dual users who vaped and smoked) and 25 controls who neither vaped nor smoked. E-liquid samples before (dispenser e-liquid) and after (tank e-liquid) being added to their devices were collected. Aerosol samples were collected using a condensation method. All participants provided urine and hair samples. All samples were analyzed for metals by ICP-MS. We observed higher metal concentrations in the aerosol and tank e-liquid (in contact with the coil) compared to the dispenser e-liquid (before contact with the coil). The median concentrations for some of the metals with the most remarkable increases in aerosol and tank e-liquid vs. dispenser e-liquid were 36.90 and 62.73 vs. 18.29 μg/kg for Al; 6.71 and 28.97 vs. 0.98 μg/kg for Cr; 91.39 and 414.47 vs. 1.64 μg/kg for Ni; 738.99 and 744.24 vs. 16.56 μg/kg for Zn; and 10.17 and 22.31 vs. 0.88 μg/kg for Pb. We also found detectable and potentially high concentrations of other metals such as Mn, Cu, Sb and Sn. In urine, increases in the median levels (μg/g creatinine) in vapers/duals vs. controls were observed for some metals, including Cr (0.34/0.28 vs. 0.20), Cu (1.72/2.36 vs. 1.46), Sn (0.26/0.31 vs. 0.18) and Pb (0.39/0.44 vs. 0.22). In hair, there were no differences in metal concentrations among the three groups. In conclusion, e-cigarettes are likely a source of metals such as Cr, Cu, Ni, Pb or Sn. These metals come from the device, likely the heating resistance, as their concentrations were low in the dispenser e-liquid and higher in the aerosol and the e-liquid left in the tank. Although the exposure to e-cigarette aerosol can have an influence in the body burden of metals, aerosol metal levels were not clearly associated with metal levels in biological samples such as urine or hair in e-cigarette users in this study.

Spatial relationship between well water arsenic and uranium in Northern Plains native lands

Arsenic and uranium in unregulated private wells affect many rural populations across the US. The distribution of these contaminants in the private wells of most American Indian communities is poorly characterized, and seldom studied together. Here, we evaluate the association between drinking water arsenic and uranium levels in wells (n = 441) from three tribal regions in North Dakota and South Dakota participating in the Strong Heart Water Study. Groundwater contamination was extensive; 29% and 7% of wells exceeded maximum contaminant levels for arsenic and uranium respectively. 81% of wells had both arsenic and uranium concentrations at one-tenth of their human-health benchmark (arsenic, 1 μg/L; uranium 3 μg/L). Well arsenic and uranium concentrations were uncorrelated (rs = 0.06); however, there appeared to be a spatial correlation of wells co-contaminated by arsenic and uranium associated with flow along a geologic contact. These findings indicate the importance of measuring multiple metals in well water, and to understand underlying hydrogeological conditions. The underlying mechanisms for the prevalence of arsenic and uranium across Northern Plains Tribal Lands in the US, and in particular the occurrence of both elevated arsenic and uranium in drinking water wells in this region, demands further study.

Blood cadmium and physical function limitations in older adults

BACKGROUND

Cadmium (Cd) is a toxic metal found in tobacco, air and food. Recent cross-sectional studies have suggested that Cd negatively impacts physical performance, but the prospective association is uncertain.

METHODS

We used data from 2548 older adults from the Seniors-ENRICA II cohort in Madrid, Spain. Whole blood Cd levels were measured at baseline using inductively coupled plasma-mass spectrometry. At baseline (2017) and follow-up (2019), overall physical function was evaluated using the physical component summary (PCS) of the SF 12-Item Health questionnaire, lower-extremity performance with the Short Physical Performance Battery (SPPB), muscle weakness with a hand dynamometer, and frailty with a Deficit Accumulation index. Mobility limitations and disability in instrumental activities of daily living (IADL) were ascertained with standardized questionnaires. Analyses were adjusted for relevant confounders, including tobacco smoke, number of cigarettes smoked per day and time since cessation in former smokers.

RESULTS

In cross-sectional analyses, odds ratios (95% confidence interval) per two-fold increase in blood Cd were 1.16 (1.03; 1.31) for low PCS scores, 1.08 (0.97; 1.20) for impaired lower-extremity performance, 1.10 (0.98; 1.23) for low grip strength, 1.11 (1.02; 1.20) for mobility limitations, 1.16 (1.02; 1.31) for frailty, and 1.26 (1.08; 1.47) for IADL disability. In longitudinal analyses, corresponding hazard ratios were 1.25 (1.03; 1.51) for low PCS scores, 1.14 (1.03; 1.27) for impaired lower-extremity performance, 1.02 (0.92; 1.13) for low grip strength, 1.03 (0.91; 1.16) for mobility limitations, and 1.16 (1.00; 1.35) for frailty. All the associations where consistent when current smokers were excluded from the analyses.

CONCLUSIONS

Our results support the role of Cd as a risk factor for physical function impairments in older adults.

E-cigarette aerosol collection using converging and straight tubing Sections: Physical mechanisms

HYPOTHESIS

Identification and quantification of harmful chemicals in e-cigarette aerosol requires collecting the aerosolized e-liquid for chemical analysis. In 2016, Olmedo at al. empirically developed a simple method for aerosol collection by directing the aerosol through a sequence of alternating straight and converging tubing sections, which drain the recovered e-liquid into a collection vial. The tubing system geometry and flow conditions promote inertial impaction of aerosolized e-liquid on tube walls, where it deposits and flows into the collection vial.

EXPERIMENTS

We use high-speed optical imaging to visualize aerosol transport in proxies of the collection system. We also determined collection efficiencies of various configurations of the collection system.

FINDINGS

A turbulent jet emerges from converging conical sections and impinges onto the wall of downstream tubing sections, resulting in inertial impaction and deposition of the aerosol. For inertial impaction to occur the tip radius of the converging section must be small enough for a jet to be formed and the sequence of tubing sections must be curved in a polygon-like manner such that the jet emerging from a converging section impinges on the downstream tube wall. The collection efficiency is significantly smaller without such curvature.

Selenium and impaired physical function in US and Spanish older adults

Background

Selenium (Se) is a trace element with a narrow safety margin.

Objectives

To evaluate the cross-sectional and longitudinal dose-response association between Se exposure and measures of impaired physical function and disability in older adults.

Design

NHANES 2011–2014 cross-sectional (US, n = 1733, age ≥60 years) and Seniors-ENRICA-2 2017–2019 cross-sectional and longitudinal (Spain, n = 2548 and 1741, respectively, age ≥65 years) data were analyzed. Whole blood and serum Se levels were measured using inductively coupled plasma-mass spectrometry. Lower-extremity performance was assessed with the Short Physical Performance Battery, and muscle weakness with a dynamometer. Incident mobility and agility limitations, and disability in instrumental activities of daily living (IADL) were ascertained with standardized questionnaires. Analyses were adjusted for relevant confounders, including physical activity. Results across studies were pooled using random-effects meta-analysis.

Results

Meta-analyzed odds ratios (95% confidence interval) per log2 increase in whole blood Se were 0.54 (0.32; 0.76) for weakness, 0.59 (0.34; 0.83) for impaired lower-extremity performance, 0.48 (0.31; 0.68) for mobility limitations, 0.71 (0.45; 0.97) for agility limitations, and 0.34 (0.12; 0.56) for disability in at least one IADL. Analyses for serum Se in NHANES showed similar results. Findings suggest the inverse association with grip strength is progressive below 140 μg/L (p-value for non-linear trend in the Seniors-ENRICA-2 study = 0.13), and above 140 μg/L (p-value for non-linear trend in NHANES = 0.11). In the Seniors-ENRICA-2 cohort, with a 2.2 year follow-up period, a doubling in baseline Se levels were associated with a lower incidence of weakness [odds ratio (95% confidence interval): 0.45 (0.22; 0.91)], impaired lower-extremity performance [0.63 (0.32; 1.23)], mobility [0.43 (0.21; 0.91)] and agility [0.38 (0.18; 0.78)] limitations.

Discussion

In US and Spanish older adults, Se concentrations were inversely associated with physical function limitations. Further studies are needed to elucidate underlying mechanisms.

E-cigarette use behaviors and device characteristics of daily exclusive e-cigarette users in Maryland: Implications for product toxicity

INTRODUCTION

Few studies to date have characterized daily exclusive e-cigarette users, device characteristics, and use behaviors. This study describes daily e-cigarette user characteristics, and assesses the association between user behaviors and demographics.

METHODS

From 2015–2017, 100 daily exclusive e-cigarette users and 50 non-users were recruited in Maryland, USA. Sociodemographic characteristics, health status, e-cigarette/tobacco use behaviors, device characteristics, and reasons for e-cigarette use were collected by interview. Chi-squared tests (categorical variables), Student’s t-test (continuous variables), and linear regressions were used to assess relationships between variables.

RESULTS

Most daily exclusive e-cigarette users were men, White, former smokers, used MODs/tanks, and vaped on average 365 puffs/day (SD: 720). A third of users first vaped within 5 minutes of waking in the morning, and 56% vaped throughout the day. E-liquid consumption ranged from 5–240 mL/week (median: 32.5), with nicotine concentration 0–24 mg/mL (median: 3). E-cigarette users were more likely to report wheezing/whistling and hypertension than controls, although the finding was not statistically significant after adjustment. Less than half planned to quit vaping.

CONCLUSIONS

Daily e-cigarette users between 2015–2017 most commonly vaped MOD/tank devices. Being male and of lower education was associated with higher usage. Daily users with no intention to quit may be at risk for increased exposure to emissions from e-cigarettes that include inorganic (metals) and organic (e.g. acrolein, formaldehyde) compounds with known toxic effects, particularly to the lung. Further research is needed to characterize the long-term health effects of daily e-cigarette use.

Low serum iron levels and risk of cardiovascular disease in high risk elderly population: Nested case-control study in the PREvención con DIeta MEDiterránea (PREDIMED) trial

BACKGROUND & AIMS

Epidemiological data on iron status and cardiovascular disease (CVD) are still controversial. The aim of this study was to determine whether low serum iron (SI) levels are associated with an increased odds of first CVD event in a population at high cardiovascular risk.

METHODS

Case-control study design nested within the "PREvención con DIeta MEDiterránea" (PREDIMED) trial. A total of 207 participants diagnosed with CVD (myocardial infarction, stroke or cardiovascular death) during follow-up period (2003-2010) were matched by sex, age and intervention group to 436 controls by incidence density sampling. Median time between serum sample collection and subsequent CVD event occurrence was 0.94 years. Inductively coupled plasma mass spectrometry analysis was used to determine SI levels. In-person interviews, medical record reviews, and validated questionnaires were used to assess covariates. Multivariable-adjusted odds ratios (ORs) of CVD were calculated with conditional logistic regression.

RESULTS

Mean SI levels were higher in men than in women (1224.0 μg/L vs. 1093.8 μg/L; p < 0.001). Among women, but not in men, the mean SI concentration was lower in cases than in controls (1008.5 μg/L vs. 1132.9 μg/L; p = 0.030). There was a gradual decrease in the multivariable-adjusted ORs of CVD with increasing SI levels (highest vs. lowest quartile: OR = 0.55, 95% CI: 0.32-0.93; p_trend = 0.020). This inverse relationship was more pronounced among women (highest vs. lowest quartile: OR = 0.15, 95% CI: 0.03-0.69; p_trend = 0.011).

CONCLUSIONS

The present findings are consistent with previously reported inverse associations between SI and CVD. SI levels as an independent marker of short-term cardiovascular risk may be useful for risk assessment in older populations.

TRIAL REGISTRATION

www.controlled-trials.com; International Standard Randomized Controlled Trial Number (ISRCTN): 35,739,639. Registered 5 October 2005. Retrospectively registered.

Association of urinary metal concentrations with blood pressure and serum hormones in Spanish male adolescents

OBJECTIVE

To examine the association of urinary concentrations of arsenic (As), cadmium (Cd), mercury (Hg), nickel (Ni), lead (Pb), manganese (Mn), and chromium (Cr) with blood pressure (BP) and serum hormone levels in male adolescents.

METHODS

Participants were selected from the INMA (Environment and Childhood)-Granada cohort at their follow-up visit when aged 15-17 years. Metal concentrations were measured in urine samples using inductively coupled plasma mass spectrometry. Outcomes were BP measurements (systolic, diastolic, and pulse pressure) recorded during the visit and concurrent serum levels of thyroid hormones, sex hormones, and adrenal hormones. Associations were assessed by regression analysis in a sub-sample of 133 boys with available data on urinary metals, outcomes, and relevant covariates.

RESULTS

Models simultaneously adjusted for all metals and other potential confounders showed that urinary As and Cd were both associated with slight elevations in systolic BP (0.70 mmHg, 95%CI = 0.11; 1.29 and 1.47, 95%CI = 0.30; 2.63, respectively, per each 50% increase in metal concentrations), and urinary As was also associated with an increased risk of elevated systolic BP (≥120 mmHg) (OR = 1.28, 95%CI = 1.04; 1.56). The presence of detectable levels of 4 and 5 versus 2-3 non-essential metals (As, Cd, Hg, Ni, Pb) per boy was associated with elevations in systolic BP of 5.84 mmHg (95%CI = 0.40; 11.3) and 7.01 mmHg (95%CI = 1.01; 13.0), respectively (p-trend = 0.05). Significant associations were also found between Hg and increased testosterone and luteinizing hormone (LH) and decreased thyroid-stimulating hormone (TSH); between the combination of As and Hg and increased LH and insulin-like growth factor 1; between Cr and decreased TSH; and between Cd and increased adrenocorticotropic hormone.

CONCLUSIONS

These findings suggest that combined exposure to toxic metals, especially As and Cd, may contribute to BP elevation in male adolescents and that exposure to Hg, As, Cd, and Cr may affect their hormone levels.

Metal/Metalloid Levels in Electronic Cigarette Liquids, Aerosols, and Human Biosamples: A Systematic Review

BACKGROUND

Electronic cigarettes (e-cigarettes) have become popular, in part because they are perceived as a safer alternative to tobacco cigarettes. An increasing number of studies, however, have found toxic metals/metalloids in e-cigarette emissions.

OBJECTIVE

We summarized the evidence on metal/metalloid levels in e-cigarette liquid (e-liquid), aerosols, and biosamples of e-cigarette users across e-cigarette device systems to evaluate metal/metalloid exposure levels for e-cigarette users and the potential implications on health outcomes.

METHODS

We searched PubMed/TOXLINE, Embase®, and Web of Science for studies on metals/metalloids in e-liquid, e-cigarette aerosols, and biosamples of e-cigarette users. For metal/metalloid levels in e-liquid and aerosol samples, we collected the mean and standard deviation (SD) if these values were reported, derived mean and SD by using automated software to infer them if data were reported in a figure, or calculated the overall mean (mean ± SD) if data were reported only for separate groups. Metal/metalloid levels in e-liquids and aerosols were converted and reported in micrograms per kilogram and nanograms per puff, respectively, for easy comparison.

RESULTS

We identified 24 studies on metals/metalloids in e-liquid, e-cigarette aerosols, and human biosamples of e-cigarette users. Metal/metalloid levels, including aluminum, antimony, arsenic, cadmium, cobalt, chromium, copper, iron, lead, manganese, nickel, selenium, tin, and zinc, were present in e-cigarette samples in the studies reviewed. Twelve studies reported metal/metalloid levels in e-liquids (bottles, cartridges, open wick, and tank), 12 studies reported metal/metalloid levels in e-cigarette aerosols (from cig-a-like and tank devices), and 4 studies reported metal/metalloid levels in human biosamples (urine, saliva, serum, and blood) of e-cigarette users. Metal/metalloid levels showed substantial heterogeneity depending on sample type, source of e-liquid, and device type. Metal/metalloid levels in e-liquid from cartridges or tank/open wicks were higher than those from bottles, possibly due to coil contact. Most metal/metalloid levels found in biosamples of e-cigarette users were similar or higher than levels found in biosamples of conventional cigarette users, and even higher than those found in biosamples of cigar users.

CONCLUSION

E-cigarettes are a potential source of exposure to metals/metalloids. Differences in collection methods and puffing regimes likely contribute to the variability in metal/metalloid levels across studies, making comparison across studies difficult. Standardized protocols for the quantification of metal/metalloid levels from e-cigarette samples are needed. https://doi.org/10.1289/EHP5686.

Dietary determinants of inorganic arsenic exposure in the Strong Heart Family Study

BACKGROUND

Chronic exposure to inorganic arsenic (iAs) in the US occurs mainly through drinking water and diet. Although American Indian (AI) populations have elevated urinary arsenic concentrations compared to the general US population, dietary sources of arsenic exposure in AI populations are not well characterized.

METHODS

We evaluated food frequency questionnaires to determine the major dietary sources of urinary arsenic concentrations (measured as the sum of arsenite, arsenate, monomethylarsonate, and dimethylarsinate, ΣAs) for 1727 AI participants in the Strong Heart Family Study (SHFS). We compared geometric mean ratios (GMRs) of urinary ΣAs for an interquartile range (IQR) increase in reported food group consumption. Exploratory analyses were stratified by gender and study center.

RESULTS

In fully adjusted generalized estimating equation models, the percent increase (95% confidence interval) of urinary ΣAs per increase in reported food consumption corresponding to the IQR was 13% (5%, 21%) for organ meat, 8% (4%, 13%) for rice, 7% (2%, 13%) for processed meat, and 4% (1%, 7%) for non-alcoholic drinks. In analyses stratified by study center, the association with organ meat was only observed in North/South Dakota. Consumption of red meat [percent increase -7% (-11%, -3%)] and fries and chips [-6% (-10%, -2%)] was inversely associated with urinary ΣAs.

CONCLUSIONS

Organ meat, processed meat, rice, and non-alcoholic drinks contribute to ΣAs exposure in the SHFS population. Organ meat is a unique source of ΣAs exposure for North and South Dakota participants and may reflect local food consumption. Further studies should comprehensively evaluate drinking water arsenic in SHFS communities and determine the relative contribution of diet and drinking water to total arsenic exposure.

Quistes pulmonares congénitos en recién nacido. A propósito de un caso

Congenital pulmonary malformations, especially congenital pulmonary cysts, are a heterogeneous group of alterations in lung development that can occur at different stages of embryogenesis, affecting the parenchyma, the arterial supply, the venous drainage or being a combination of them. A clinical case is presented where it analyzes the congenital pulmonary malformations in a newborn patient at the term of adequate weight for the gestational age, in the same as when entering the Neonatology service. To the radiological control in which an image of bubbles of air trapped in the left base is visualized, initial suspicion of diaphragmatic hernia, the same that is discarded at 24 hours, changing to a diagnosis of congenital pulmonary malformations. Congenital lung cysts.

Echinococcus Granulosus in the Endangered Patagonian Huemul (Hippocamelus bisulcus)

Cystic echinococcosis (CE) is a zoonotic parasitic disease associated with Echinococcus granulosus. The parasite is maintained by domestic and wild canids as definitive hosts with several ungulate species as intermediate hosts in domestic and peridomestic transmission cycles. In Chile, CE is endemic, and the role of livestock and dogs (Canis lupus familiaris) in the cycle and the accidental infection of humans are widely documented at rural sites. However, the role of wild herbivores in wild cycles or the potential transmission of CE from livestock is still unknown in Chile and the rest of South America. We used molecular techniques to describe CE infecting a Patagonian huemul (Hippocamelus bisulcus) in Cerro Castillo National Reserve (Aysén region, Chile). We make inferences about the risk of disease spillover from sympatric domestic and wild species. The DNA-based molecular analysis revealed that the huemul was infected with E. granulosus G1 genotype, sharing haplotypes with other G1 samples collected from sheep (Ovis aries) and cattle (Bos taurus) worldwide. Geographic overlap between sheep and huemul populations in the reserve likely facilitates parasite spillover into wild deer populations, with shepherd or stray dogs and wild foxes (Lycalopex culpaeus) potentially acting as bridging hosts between livestock and the endangered huemul. Further studies are warranted to understand the implications of E. granulosus for huemul conservation throughout the Chilean Patagonia.

Metal concentrations in electronic cigarette aerosol: Effect of open-system and closed-system devices and power settings

BACKGROUND

Electronic cigarettes (E-cigarettes) generate aerosol containing metal contaminants. Our goals were to quantify aerosol metal concentrations and to compare the effects of power setting and device type (closed-system vs. open-system) on metal release.

METHODS

Aerosol samples were collected from two closed-system devices (a cigalike and pod) and two open-system devices (mods). Each open-system device was operated at three different power settings to examine the effect of device power on metal release. Concentrations of 14 metals in e-cigarette aerosol collected via droplet deposition were measured using inductively coupled plasma mass spectroscopy. Aerosol metal concentrations were reported as mass fractions (μg/kg) in the e-liquid.

RESULTS

For open-system device 1 (OD1), median arsenic (As), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), antimony (Sb), tin (Sn), and zinc (Zn) concentrations increased 14, 54, 17, 30, 41, 96, 14, 81, 631, and 7-fold when the device power was increased from low (20 W) to intermediate (40 W) setting. When the power was further increased from intermediate (40 W) to high (80 W) setting, concentrations of As, Cr, Cu, Mn, Ni, and Sb did not change significantly. For open-system device 2 (OD2), Cr and Mn concentrations increased significantly when device power was increased from low (40 W) to intermediate (120 W) setting, and then decreased significantly when power was further increased from intermediate (120 W) to high (200 W) setting. Among the four devices, aerosol metal concentrations were higher for the open-system than the closed-system devices, except for aluminum (Al) and uranium (U). For Cr, median (interquartile range) concentrations (μg/kg) from the open-system devices were 2.51 (1.55, 4.23) and 15.6 (7.88, 54.5) vs. 0.39 (0.05, 0.72) and 0.41 (0.34, 0.57) for the closed-system devices. For Ni, concentrations (μg/kg) from the open-system devices were 793 (508, 1169) and 2148 (851, 3397) vs. 1.32 (0.39, 3.35) and 11.9 (10.7, 22.7) from the closed-system devices. Inhalation of 0% and 100% of samples from OD1, 7.4% and 88.9% from OD2 by typical e-cigarette users would exceed chronic minimum risk levels (MRL) of Mn and Ni, respectively. No MRL exceedance was predicted for the closed-system devices. A large fraction of users of OD1 (100%) and OD2 (77.8%) would be exposed to Ni levels higher than those from reference tobacco cigarette 3R4F.

CONCLUSIONS

Our findings suggest that power setting and device type affect metal release from devices to aerosol which would subsequently be inhaled by users. Metal concentrations from open-system devices first increased with device power, and then leveled off for most metals. Open-system devices generate aerosol with higher metal concentrations than closed-system devices. These findings inform tobacco regulatory science, policy makers and health professionals on potential metal health risks associated with e-cigarette use, design and manufacturing.

Waterpipe tobacco smoke: Characterization of toxicants and exposure biomarkers in a cross-sectional study of waterpipe employees

INTRODUCTION

Few studies have comprehensively characterized toxic chemicals related to waterpipe use and secondhand waterpipe exposure. This cross-sectional study investigated biomarkers of toxicants associated with waterpipe use and passive waterpipe exposure among employees at waterpipe venues.

METHOD

We collected urine specimens from employees in waterpipe venues from Istanbul, Turkey and Moscow, Russia, and identified waterpipe and cigarette smoking status based on self-report. The final sample included 110 employees. Biomarkers of exposure to sixty chemicals (metals, volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), nicotine, and heterocyclic aromatic amines (HCAAs)) were quantified in the participants' urine.

RESULTS

Participants who reported using waterpipe had higher urinary manganese (geometric mean ratio (GMR): 2.42, 95% confidence interval (CI): 1.16, 5.07) than never/former waterpipe or cigarette smokers. Being exposed to more hours of secondhand smoke from waterpipes was associated with higher concentrations of cobalt (GMR: 1.38, 95% CI: 1.10, 1.75). Participants involved in lighting waterpipes had higher urinary cobalt (GMR: 1.43, 95% CI: 1.10, 1.86), cesium (GMR: 1.21, 95% CI: 1.00, 1.48), molybdenum (GMR: 1.45, 95% CI: 1.08, 1.93), 1-hydroxypyrene (GMR: 1.36, 95% CI: 1.03, 1.80), and several VOC metabolites.

CONCLUSION

Waterpipe tobacco users and nonsmoking employees of waterpipe venues had higher urinary concentrations of several toxic metals including manganese and cobalt as well as of VOCs, in a distinct signature compared to cigarette smoke. Employees involved in lighting waterpipes may have higher exposure to multiple toxic chemicals compared to other employees.

Arsenic in groundwater in private wells in rural North Dakota and South Dakota: Water quality assessment for an intervention trial

Elevated exposure to arsenic disproportionately affects populations relying on private well water in the United States (US). This includes many American Indian (AI) communities where naturally occurring arsenic is often above 10 µg/L, the current US Environmental Protection Agency safety standard. The Strong Heart Water Study is a randomized controlled trial aiming to reduce arsenic exposure to private well water users in AI communities in North Dakota and South Dakota. In preparation for this intervention, 371 households were included in a community water arsenic testing program to identify households with arsenic ≥10 µg/L by inductively coupled plasma mass spectrometry (ICP-MS). Arsenic ≥10 µg/L was found in 97/371 (26.1%) households; median water arsenic concentration was 6.3 µg/L, ranging from <1-198 µg/L. Silica was identified as a water quality parameter that could impact the efficacy of arsenic removal devices to be installed. A low-range field rapid arsenic testing kit evaluated in a small number of households was found to have low accuracy; therefore, not an option for the screening of affected households in this setting. In a pilot study of the effectiveness of a point-of-use adsorptive media water filtration device for arsenic removal, all devices installed removed arsenic below 1 µg/L at both installation and 9 months post-installation. This study identified a relatively high burden of arsenic in AI study communities as well as an effective water filtration device to reduce arsenic in these communities. The long-term efficacy of a community based arsenic mitigation program in reducing arsenic exposure and preventing arsenic related disease is being tested as part of the Strong Heart Water Study.

Assessment of indoor air quality at an electronic cigarette (Vaping) convention

E-cigarette (vaping) conventions are public events promoting electronic cigarettes, in which indoor use of e-cigarettes is allowed. The large concentration of people using e-cigarettes and poor air ventilation can result in indoor air pollution. In order to estimate this worst-case exposure to e-cigarettes, we evaluated indoor air quality in a vaping convention in Maryland (MD), USA. Real-time concentrations of particulate matter (PM₁₀) and real-time total volatile organic compounds (TVOCs), CO₂ and NO₂ concentrations were measured. Integrated samples of air nicotine and PM₁₀ concentrations were also collected. The number of attendees was estimated to range from 75 to 600 at any single observation time. The estimated 24-h time-weighted average (TWA) PM₁₀ was 1800 μg/m³, 12-fold higher than the EPA 24-h regulation (150 μg/m³). Median (range) indoor TVOCs concentration was 0.13 (0.04-0.3) ppm. PM₁₀ and TVOC concentrations were highly correlated with CO₂ concentrations, indicating the high number of people using e-cigarettes and poor indoor air quality. Air nicotine concentration was 125 μg/m³, equivalent to concentrations measured in bars and nightclubs. E-cigarette aerosol in a vaping convention that congregates many e-cigarette users is a major source of PM₁₀, air nicotine and VOCs, impairing indoor air quality. These findings also raise occupational concerns for e-cigarette vendors and other venue staff workers.

Metal Concentrations in e-Cigarette Liquid and Aerosol Samples: The Contribution of Metallic Coils

BACKGROUND

Electronic cigarettes (e-cigarettes) generate an aerosol by heating a solution (e-liquid) with a metallic coil. Whether metals are transferred from the coil to the aerosol is unknown.

OBJECTIVE

Our goal was to investigate the transfer of metals from the heating coil to the e-liquid in the e-cigarette tank and the generated aerosol.

METHODS

We sampled 56 e-cigarette devices from daily e-cigarette users and obtained samples from the refilling dispenser, aerosol, and remaining e-liquid in the tank. Aerosol liquid was collected via deposition of aerosol droplets in a series of conical pipette tips. Metals were reported as mass fractions (μg/kg) in liquids and converted to mass concentrations (mg/m³) for aerosols.

RESULTS

Median metal concentrations (μg/kg) were higher in samples from the aerosol and tank vs. the dispenser (all p<0.001): 16.3 and 31.2 vs. 10.9 for Al; 8.38 and 55.4 vs. <0.5 for Cr; 68.4 and 233 vs. 2.03 for Ni; 14.8 and 40.2 vs. 0.476 for Pb; and 515 and 426 vs. 13.1 for Zn. Mn, Fe, Cu, Sb, and Sn were detectable in most samples. Cd was detected in 0.0, 30.4, and 55.1% of the dispenser, aerosol, and tank samples respectively. Arsenic was detected in 10.7% of dispenser samples (median 26.7μg/kg) and these concentrations were similar in aerosol and tank samples. Aerosol mass concentrations (mg/m³) for the detected metals spanned several orders of magnitude and exceeded current health-based limits in close to 50% or more of the samples for Cr, Mn, Ni, and Pb.

CONCLUSIONS

Our findings indicate that e-cigarettes are a potential source of exposure to toxic metals (Cr, Ni, and Pb), and to metals that are toxic when inhaled (Mn and Zn). Markedly higher concentrations in the aerosol and tank samples versus the dispenser demonstrate that coil contact induced e-liquid contamination. https://doi.org/10.1289/EHP2175.

The association of e-cigarette use with exposure to nickel and chromium: A preliminary study of non-invasive biomarkers

BACKGROUND

Nickel (Ni) and chromium (Cr) are components of e-cigarette heating coils. Whether e-cigarettes increase metal internal dose, however, is unknown. We assessed the association of e-cigarette use patterns and of e-liquid and aerosol metal concentrations with Ni and Cr biomarker levels in e-cigarette users from Maryland.

METHODS

We recruited 64 e-cigarette users from December 2015 to March 2016. We collected urine, saliva, and exhaled breath condensate (EBC), data on e-cigarette use, and samples from their e-cigarette device (dispenser e-liquid, aerosol, and tank e-liquid).

RESULTS

Median Ni and Cr levels were 0.73 and 0.39μg/g creatinine in urine, 2.25 and 1.53μg/L in saliva, and 1.25 and 0.29μg/L in EBC. In adjusted models, tertiles 2 and 3 of aerosol Ni concentrations were associated with 16% and 72% higher urine Ni and 202% and 321% higher saliva Ni compared to the lowest tertile. Tertile 3 of aerosol Cr levels were associated with 193% higher saliva Cr. An earlier time to first vape in the morning and more frequent coil change were associated with higher urine Ni. Tertile 2 of e-liquid consumption per week and voltage were associated with higher saliva Ni levels than tertile 1.

CONCLUSION

Positive associations of Ni and Cr aerosol concentrations with corresponding Ni and Cr biomarker levels indicate e-cigarette emissions increase metal internal dose. Increased e-cigarette use and consumption were also associated with higher Ni biomarker levels. Metal level standards are needed to prevent involuntary metal exposure among e-cigarette users.

E-cigarettes as a source of toxic and potentially carcinogenic metals

BACKGROUND AND AIMS

The popularity of electronic cigarette devices is growing worldwide. The health impact of e-cigarette use, however, remains unclear. E-cigarettes are marketed as a safer alternative to cigarettes. The aim of this research was the characterization and quantification of toxic metal concentrations in five, nationally popular brands of cig-a-like e-cigarettes.

METHODS

We analyzed the cartomizer liquid in 10 cartomizer refills for each of five brands by Inductively Coupled Plasma Mass Spectrometry (ICP-MS).

RESULTS

All of the tested metals (cadmium, chromium, lead, manganese and nickel) were found in the e-liquids analyzed. Across all analyzed brands, mean (SD) concentrations ranged from 4.89 (0.893) to 1970 (1540) μg/L for lead, 53.9 (6.95) to 2110 (5220) μg/L for chromium and 58.7 (22.4) to 22,600 (24,400) μg/L for nickel. Manganese concentrations ranged from 28.7 (9.79) to 6910.2 (12,200) μg/L. We found marked variability in nickel and chromium concentration within and between brands, which may come from heating elements.

CONCLUSION

Additional research is needed to evaluate whether e-cigarettes represent a relevant exposure pathway for toxic metals in users.

Dietary determinants of cadmium exposure in the Strong Heart Family Study

Urinary cadmium (Cd) concentrations in the Strong Heart Family Study (SHFS) participants are higher than in the general US population. This difference is unlikely to be related to tobacco smoking. We evaluated the association of consumption of processed meats and other dietary products with urinary Cd concentrations in the SHFS, a family-based study conducted in American Indian communities. We included 1725 participants with urine Cd concentrations (standardized to urine creatinine) and food frequency questionnaire data grouped in 24 categories, including processed meat. Median (IQR) urinary Cd concentrations were 0.42 (0.20-0.85) μg/g creatinine. The age, sex, smoking, education, center, body mass index, and total kcal adjusted geometric mean ratio (GMR) (95%CI) of urinary cadmium concentrations per IQR increase in each dietary category was 1.16 (1.04-1.29) for processed meat, 1.10 (1.00-1.21) for fries and chips, 0.87 (0.80-0.95) for dairy products, and 0.89 (0.82-0.97) for fruit juices. The results remained similar after further adjustment for the dietary categories associated with urinary Cd in the previous model except for fries and chips, which was no longer statistically significant. These findings revealed the potential importance of processed meat products as a dietary source of cadmium.

Gene-environment interactions between ERCC2, ERCC3, XRCC1 and cadmium exposure in nasal polyposis disease

Gene-environment interactions have long been known to play an important role in complex disease aetiology, such as nasal polyposis (NP). The present study supports the concept that DNA repair gene polymorphisms play critical roles in modifying individual susceptibility to environmental diseases. In fact, we investigated the role of polymorphisms in DNA repair genes and cadmium as risk factors for Tunisian patients with NP. To the best of our knowledge, this is the first report on the impact of combined effects of cadmium and ERCC3 7122 A>G (rs4150407), ERCC2 Lys751Gln (rs13181) and XRCC1 Arg399Gln (rs25487) genes in the susceptibility to NP disease. Significant associations between the risk of developing NP disease and ERCC2 [odds ratio (OR) = 2.0, 95 % confidence interval (CI) = 1.1-3.7, p = 0.023] and ERCC3 (OR = 2.2, 95 % CI = 1.2-4.1, p = 0.013) genotypes polymorphisms were observed. Blood concentrations of Cd in NP patients (2.2 μg/L) were significantly higher than those of controls (0.5 μg/L). A significant interaction between ERCC3 (7122 A>G) polymorphism and blood-Cd levels (for the median of blood-Cd levels: OR = 3.8, 95 % CI = 1.3-10.8, p = 0.014 and for the 75th percentiles of blood-Cd levels: OR = 2.7, 95 % CI = 1.1-7.2, p = 0.041) was found in association with the risk of NP disease. In addition, when we stratified ERCC2, ERCC3 and XRCC1 polymorphism genotypes by the median and 75th percentiles of blood-Cd levels, we found also significant interactions between ERCC2 (Lys751Gln) and ERCC3 (7122 A>G) genotypes polymorphism and this metal in association with NP disease. However, no interaction was found between XRCC1 (Arg399Gln) polymorphism genotypes and Cd in association with NP disease.

A direct method for e-cigarette aerosol sample collection

E-cigarette use is increasing in populations around the world. Recent evidence has shown that the aerosol produced by e-cigarettes can contain a variety of toxicants. Published studies characterizing toxicants in e-cigarette aerosol have relied on filters, impingers or sorbent tubes, which are methods that require diluting or extracting the sample in a solution during collection. We have developed a collection system that directly condenses e-cigarette aerosol samples for chemical and toxicological analyses. The collection system consists of several cut pipette tips connected with short pieces of tubing. The pipette tip-based collection system can be connected to a peristaltic pump, a vacuum pump, or directly to an e-cigarette user for the e-cigarette aerosol to flow through the system. The pipette tip-based system condenses the aerosol produced by the e-cigarette and collects a liquid sample that is ready for analysis without the need of intermediate extraction solutions. We tested a total of 20 e-cigarettes from 5 different brands commercially available in Maryland. The pipette tip-based collection system condensed between 0.23 and 0.53mL of post-vaped e-liquid after 150 puffs. The proposed method is highly adaptable, can be used during field work and in experimental settings, and allows collecting aerosol samples from a wide variety of e-cigarette devices, yielding a condensate of the likely exact substance that is being delivered to the lungs.

Association between blood arsenic levels and nasal polyposis disease risk in the Tunisian population

Although the pathophysiology underlying nasal polyposis (NP) formation is not fully understood, systemic, local, and environmental factors appear to contribute to NP disease development. This study aimed to explore the relationship between metal blood levels and NP risk. To the best of our knowledge, the current research represents the first scientific contribution reporting levels of Cr and As in blood of NP patients. In this context, 90 NP patients and 171 controls were recruited and blood samples were analyzed to determine the concentrations of As and Cr. Metal blood levels of As in patients (2.1 μg/L) were significantly higher than those of controls (1.2 μg/L). However, no significant difference in blood Cr levels was found between cases and controls. Arsenic blood levels of cigarette smokers were significantly higher than those of non-smokers. Environmental exposure and shisha consumption presented the most significant association with NP disease (OR = 10.1 and 14.1, respectively). High levels of blood As were significantly associated with NP disease (OR = 2.1). Cr blood levels were found to be associated with the four stages of polyps in both nasal cavities. This study found a strong association between nasal polyposis disease and As blood levels. These findings merit further investigation.

Cadmium and nickel in blood of Tunisian population and risk of nasosinusal polyposis disease

Nasosinusal polyposis (NSP) is a chronic inflammatory disease of the nasal mucosa. Although the pathophysiology underlying NSP formation is not fully understood, environmental factors appear to be contributed the development of this disease. A case-control study of Tunisian patients was examined to assess the levels of cadmium (Cd) and nickel (Ni) in blood and reparse the association between the exposure to these metals and the risk of nasosinusal polyposis disease. Mean blood levels of Cd in patients (2.2 ± 12.8 μg/L) were significantly higher than those of controls (0.5 ± 0.7 μg/L). Levels of blood Cd were positively correlated with tobacco smoking and chewing among controls. The Cd and Ni concentrations among control (p = 0.001) and patient (p = 0.018) tobacco consumers (smoking, chewing, and shisha) were significantly higher than those nonconsumers. Additionally, Ni blood levels of patient and control smokers were significantly higher than those of nonsmokers. Cd levels in blood samples of NSP patients occupationally exposed for more than 14 years were eight times higher than that of nonexposed. Drinking water was also found to be incriminated as exposure sources. Among risk factors, shisha consumption, environmental exposure, and occupational exposure presented the most significant association with NSP disease (odds ratio (OR) = 14.1, 10.1, and 1.7, respectively). High levels of blood Cd (OR = 3.5) were strongly associated with NSP disease (p = 0.027). Ni blood levels were shown to be associated with the four stages of polyps in both nasal cavities (right and left) (p < 0.05). This investigation suggested a potential role of toxic metals in the mechanism of NSP disease development. Exposure assessment investigations encompassing a wider population are needed.

Heavy metals in normal mucosa and nasal polyp tissues from Tunisian patients

Despite growing evidence that bacteria, fungi, allergens, and superantigens play a prominent role in the pathophysiology of nasal polyps (NP), the exact cause of polyposis is still unknown. The etiology of NP is considered multifactorial. Until now, there is no information on the presence of heavy metals, such as cadmium (Cd), chromium (Cr), nickel (Ni), and arsenic (As) or of their role, in the pathogenesis of NP disease. In this study, concentrations of these four metals in tissue of NP were determined using Atomic Absorption Spectrometry. The Ni, Cr, and As levels in NP tissues were 2.1-, 3.2-, and 8.0-fold higher than those of normal mucosa (p < 0.05), respectively. A strong effect of cumulative smoking as expressed in the number of pack per year (PY), Ni, As, and Cd levels in NP tissue samples of patients ever-smokers (1-20 and >20 PY) are significantly higher than those of non-smokers (p = 0.006, 0.002, and < 0.001, respectively). The highest As concentrations among patients lived at polluted areas (1-25 and > 25 years) were observed in both nasal mucosa and NP tissues. The Ni and As in both nasal mucosa and NP tissues of patients occupationally exposed were significantly higher than non-exposed group. Cr and As levels were found to be associated with NP stage classification (p < 0.05). This is the first report to describe an association between concentrations of metals (Cr, As, and Ni) in human NP tissues and the risk of NP disease. Tissue metal levels have increased due to smoking, environmental, and occupational exposure. Therefore, heavy metal exposure may increase the risk of NP in the Tunisian population. The considerable risk in the category of highest cumulative exposure argues for an association between heavy metals exposure and nasal polyposis risk. Future investigations with larger samples should better elucidate this association.

Trace metal quantification in bladder biopsies from tumoral lesions of Tunisian cancer and controls subjects

The incidence of bladder tumors has been dramatically increasing since the 1970s, possibly as a consequence of ongoing environmental pollution. Previous studies have provided some evidence of an association between cancer and exposure to carcinogenic metals. In order to examine the association between levels of toxic metals in patients with bladder tumors and controls, the amounts of arsenic, cadmium, chromium, and nickel were measured in tumoral lesions and adjacent normal part of the bladder mucosa excised for carcinoma and compared with those in the bladder mucosa of volunteer subjects operated for non-neoplastic diseases. The quantification of metals in tissue was assessed by atomic absorption spectroscopy. In tumoral tissues of the excised bladder mucosa, content of Cr and Ni was significantly low compared to that of adjacent normal tissues and control tissues while that of As and Cd in normal tissues adjacent to the tumor were significantly elevated compared to controls. Though the sample size was small, the present study shows that concentrations of metals such as Cd, Cr, As, and Ni in bladder tissue may be used as a biomarker of exposure. On the basis of the results obtained in this study, high amounts of As and Cd in adjacent normal parts of the bladders with carcinomas compared to controls would strongly suggest possible, individual or synergistic, effects of these pollutants on enzymatic systems, priming an oncogenic pathway.

Biomonitoring of cadmium, chromium, nickel and arsenic in general population living near mining and active industrial areas in Southern Tunisia

The human health impact of the historic and current mining and industrial activities in Tunisia is not known. This study assessed the exposure to metals in the population of Southern Tunisia, using biomonitoring. The aim of this pilot study was to evaluate metal exposure on 350 participants living near mining and active industrial areas in the South of Tunisia. Blood specimens were analyzed for metals (Cd, Cr, As, and Ni) by Atomic Absorption Spectrometer equipped with Zeeman background correction and AS-800 auto sampler by graphite furnace and graphite tubes with integrated L'vov platform. The sample population was classified according to different age groups, sex, smoking habit, sea food and water drinking consumption, occupational exposure, amalgam fillings and place of residence. The blood As, Cd, Cr and Ni values expressed as mean ± SD were 1.56 ± 2.49, 0.74 ± 1.15, 35.04 ± 26.02 and 30.56 ± 29.96 μg/l, respectively. Blood Cd and Ni levels in smokers were 2 and 1.2 times, respectively, higher than in non-smokers. Blood Cd levels increase significantly with age (p = 0.002). As, Cd and Ni were significantly correlated with gender and age (p < 0.05). Cd level in blood samples of subjects occupationally exposed was 1.3 times higher than that of non-exposed. Blood metals were not significantly affected by amalgam fillings, place of living and sea food and drinking water consumption. This first biomonitoring study of metal exposure in the South of Tunisia reveals a substantial exposure to several metals. The pathways of exposure and health significance of these findings need to be further investigated.

Risk of laryngeal and nasopharyngeal cancer associated with arsenic and cadmium in the Tunisian population

Chronic exposure to heavy metals has long been recognized as being capable of increasing head and neck cancer (HNC) incidence, such as laryngeal (LC) and nasopharyngeal (NPC), among exposed human populations. The aim of the present study was to evaluate the concentrations of arsenic (As) and cadmium (Cd) in the blood of 145 patients (LC and NPC) and 351 controls in order to establish a potential relationship between these factors and the occurrence of LC and NPC. Mean blood levels of As and Cd in patients (5.67 and 3.51 μg/L, respectively) were significantly higher than those of controls (1.57 and 0.74 μg/L, respectively). The blood levels of As and Cd were mostly significantly higher than those of controls (p<0.05) after controlling the other risk factors of HNC including tobacco smoking and chewing, and alcohol drinking. Cd levels in blood increase significantly with the number of occupational exposure years for patients (p<0.05). However, seafood was not found to be contributing as an exposure source. Among these risk factors, smoking (>30 pack years) and occupational exposure (>20 years) presented the most significant association with HNC (OR=10.22 and 10.38, respectively, p<0.001). Cd level in blood sample of cases that are occupationally exposed/tobacco users (smokers and chewers) were higher than that of non-occupationally exposed/nontobacco users (p<0.001). The logistic regression model illustrated that HNC (LC+NPC) was significantly associated with blood levels of As (OR=2.41, p<0.001) and Cd (OR=4.95, p<0.001).

Blood nickel and chromium levels in association with smoking and occupational exposure among head and neck cancer patients in Tunisia

Chronic exposure to chromium (Cr) and nickel (Ni) has long been recognized as being capable to increase head and neck cancer (HNC) incidence among exposed human populations. This study represents the first biomonitoring of Cr and Ni exposure in Tunisia and focuses on a possible association with HNC risk. The aim of the present study was to evaluate the concentrations of Cr and Ni in the blood of HNC patients and controls. Metals blood levels of 169 HNC patients and 351 controls were determined using a Perkin-Elmer Analyst 800 Atomic Absorption Spectrometer. Mean blood levels of Cr and Ni in HNC cases (52.15 and 111.60 μg/L, respectively) were significantly higher than those of controls (37.04 and 30.50 μg/L, respectively). Cases' blood levels of Cr and Ni were significantly higher than those of controls after controlling for the other risk factors of HNC, including smoking, shisha consumption, occupational exposure, and nearby environment (P<0.05). Among these risk factors, smoking and occupational exposure presented the most significant association with HNC (odds ratio (OR)=6.54 and 7.66, respectively, P<0.001). Cr and Ni levels in blood sample of cases and controls that are smoker/occupationally exposed were higher than that of non-smoker/non-occupationally exposed (P<0.05). Smokers who are occupationally exposed present the most significant association with HNC (OR=25.08, P<0.0001). High levels of blood Cr (OR=2.09) and high levels of blood Ni (OR=8.87) were strongly associated with HNC after other potential confounders were controlled (P=0.004 and P<0.0001, respectively). This study suggested a potential role of Cr and Ni in the mechanism of HNC development.

Cadmium in blood of Tunisian men and risk of bladder cancer: interactions with arsenic exposure and smoking

Prior investigations identified an association between low-level blood arsenic (As) and bladder cancer risk among Tunisian men but questions remain regarding confounding by cadmium (Cd), a well-established bladder carcinogen. A case-control study of Tunisian men was re-examined to assess the levels of cadmium in blood and reparse the association between the simultaneous exposure to these metals and bladder cancer risk. Levels of blood Cd were significantly twice higher among cases than in controls (P<0.05) and were positively correlated with smoking and age. Additionally, analysis of metal levels among non-smokers according to the region of residence showed very high blood Cd and As levels for the coastal regions of Sfax and central Tunisia. After controlling for potential confounders, for low blood As levels (<0.67 μg/L), the OR for blood Cd was 4.10 (95 % CI 1.64-10.81), while for higher levels (>0.67 μg/L), it was reduced to 2.10 (CI, 1.06-4.17). Adjustment for Cd exposure did not alter the risk associated to As exposure. This study is the first to report the relationship between Cd exposure and risk of bladder cancer occurrence in interaction with smoking and As exposure. Smoking is shown to be the main exposure source to Cd in the Tunisian population but also environmental pollution seems to be responsible of Cd exposure among non-smokers. Exposure assessment studies encompassing a wider population are needed.

Determination of toxic elements (mercury, cadmium, lead, tin and arsenic) in fish and shellfish samples. Risk assessment for the consumers

Although fish intake has potential health benefits, the presence of metal contamination in seafood has raised public health concerns. In this study, levels of mercury, cadmium, lead, tin and arsenic have been determined in fresh, canned and frozen fish and shellfish products and compared with the maximum levels currently in force. In a further step, potential human health risks for the consumers were assessed. A total of 485 samples of the 43 most frequently consumed fish and shellfish species in Andalusia (Southern Spain) were analyzed for their toxic elements content. High mercury concentrations were found in some predatory species (blue shark, cat shark, swordfish and tuna), although they were below the regulatory maximum levels. In the case of cadmium, bivalve mollusks such as canned clams and mussels presented higher concentrations than fish, but almost none of the samples analyzed exceeded the maximum levels. Lead concentrations were almost negligible with the exception of frozen common sole, which showed median levels above the legal limit. Tin levels in canned products were far below the maximum regulatory limit, indicating that no significant tin was transferred from the can. Arsenic concentrations were higher in crustaceans such as fresh and frozen shrimps. The risk assessment performed indicated that fish and shellfish products were safe for the average consumer, although a potential risk cannot be dismissed for regular or excessive consumers of particular fish species, such as tuna, swordfish, blue shark and cat shark (for mercury) and common sole (for lead).