Urinary arsenic and spontaneous pregnancy loss - a hypothesis-generating case-control investigation in western Romania.

Arsenic occurs as a natural contaminant of drinking water supplies in arsenic endemic areas, posing a threat to public health. Our aim was to evaluate the relationship between urinary arsenic concentrations and spontaneous pregnancy loss in a population with low-moderate level drinking water arsenic exposure (mostly <10 µg/L). We enrolled 150 women with incident spontaneous pregnancy losses and 150 controls with ongoing pregnancies matched by gestational age. We measured arsenic species in urine using high performance liquid chromatography paired to inductively coupled plasma mass spectrometry. Urinary arsenic was not related to spontaneous pregnancy loss in conditional logistic regression models adjusted for confounding factors. However, a 10 µg/L increase in urinary arsenic (III + V) salt concentrations was associated with 8.00-fold (95% CI: 0.68, 3.35 × 105) greater odds of spontaneous loss among women using prenatal vitamins in an interaction model (P for interaction = 0.07), although the effect estimate was imprecise. In an additional interaction model, prenatal vitamin use was associated with lower odds of loss (OR = 0.30; 95% CI: 0.13, 0.66), although the association was diminished in the presence of a 10 µg/L increase in urinary inorganic arsenic (OR = 0.44; 95% CI: 0.70, 3.22). Total urinary arsenic was associated with 1.48-fold (95% CI: 0.20, 11.35) greater odds for loss among women with urinary cotinine >50 µg/L in another interaction model (P for interaction = 0.07). These results suggest a potential modest increase in the odds of pregnancy loss associated with increased total urinary arsenic among women smoking during pregnancy (urinary cotinine >50 µg/L). Prenatal vitamin use may act as a protective factor for arsenic exposure associated pregnancy loss, but appears to be less protective with increasing urinary inorganic arsenic concentrations.

Health effects of air pollutant mixtures (volatile organic compounds, particulate matter, sulfur and nitrogen oxides) - a review of the literature.

The health risks associated with individual air pollutant exposures have been studied and documented, but in real-life, the population is exposed to a multitude of different substances, designated as mixtures. A body of literature on air pollutants indicated that the next step in air pollution research is investigating pollutant mixtures and their potential impacts on health, as a risk assessment of individual air pollutants may actually underestimate the overall risks. This review aims to synthesize the health effects related to air pollutant mixtures containing selected pollutants such as: volatile organic compounds, particulate matter, sulfur and nitrogen oxides. For this review, the PubMed database was used to search for articles published within the last decade, and we included studies assessing the associations between air pollutant mixtures and health effects. The literature search was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A number of 110 studies were included in the review from which data on pollutant mixtures, health effects, methods used, and primary results were extracted. Our review emphasized that there are a relatively small number of studies addressing the health effects of air pollutants as mixtures and there is a gap in knowledge regarding the health effects associated with these mixtures. Studying the health effects of air pollutant mixtures is challenging due to the complexity of components that mixtures may contain, and the possible interactions these different components may have.

Specific lifestyle factors and in vitro fertilization outcomes in Romanian women: a pilot study.

Background: Infertility is an important health concern worldwide. Although lifestyle habits and behaviors have been widely reported as predictors of IVF outcomes by previous studies, they have not been reported for Romanian women undergoing IVF. In this regard, our pilot study aimed to begin to address the data gap by assessing lifestyle predictors of in vitro fertilization (IVF) outcomes in Romanian women. Study design: Our pilot study included 35 participants who completed a first IVF cycle at a single infertility center. We evaluated individual self-reported lifestyle habits and behaviors as predictors of IVF outcomes, and employed principal component analysis (PCA) to characterize multiple lifestyle habits and behaviors into personal care product (PCP) use, and healthy diet and physical activity patterns as predictors of IVF outcomes. Results: Our PCA analysis showed that greater use of PCPs was associated with lower probabilities of pregnancy (RR: 0.92, 95% CI [0.87-0.98]) and live birth (RR: 0.94, 95% CI [0.88-1.01]) while, the healthy dietary habits and physical activity were associated with a higher likelihood of pregnancy, although without statistical significance (RR: 1.10, 95% CI [0.93-1.30]). Conclusions: In this pilot study we identified associations between IVF outcomes among Romanian women and certain lifestyle habits and behaviors including stress, diet and physical activity, and certain PCP use. We also estimated the joint effects of multiple lifestyle factors using PCA and found that PCP use, healthy dietary habits and physical activity were associated with IVF outcomes.

Predicting environmental risk factors in relation to health outcomes among school children from Romania using random forest model - An analysis of data from the SINPHONIE project.

BACKGROUND: Few studies have simultaneously assessed the health impact of school and home environmental factors on children, since handling multiple highly correlated environmental variables is challenging. In this study, we examined indoor home and school environments in relation to health outcomes using machine learning methods and logistic regression. METHODS: We used the data collected by the SINPHONIE (Schools Indoor Pollution and Health: Observatory Network in Europe) project in Romania, a multicenter European research study that collected comprehensive information on school and home environments, health symptoms in children, smoking, and school policies. The health outcomes were categorized as: any health symptoms, asthma, allergy and flu-like symptoms. Both logistic regression and random forest (RF) methods were used to predict the four categories of health outcomes, and the methods prediction performance was compared. RESULTS: The RF method we employed for analysis showed that common risk factors for the investigated categories of health outcomes, included: environmental tobacco smoke (ETS), dampness in the indoor school environment, male gender, air freshener use, residence located in proximity of traffic (<200 m), stressful schoolwork, and classroom noise (contributions ranged from 7.91% to 23.12%). Specificity, accuracy and area under the curve (AUC) values for most outcomes were higher when using RF compared to logistic regression, while sensitivity was similar in both methods. CONCLUSION: This study suggests that ETS, dampness in the indoor school environment, use of air fresheners, living in proximity to traffic (<200 m) and noise are common environmental risk factors for the investigated health outcomes. RF pointed out better predictive values, sensitivity and accuracy compared to logistic regression.

Interactions between dietary habits and home environmental exposures on respiratory symptoms in Romanian school children: an analysis of data from the SINPHONIE project.

In this study, we investigated the interactions between household pollutants and dietary habits on children's respiratory health. Our cross-sectional study collected self-reported information including health symptoms (allergy-like, asthma-like, and flu-like symptoms), home characteristics, dietary habits, and demographic information from questionnaires administered to parents of 280 school children in Romania. Unconditional logistic regression and stratified analyses were used to assess the interactions between dietary factors and environmental exposures on health symptoms among children, controlling for sociodemographic characteristics and co-exposures. We found that frequency of fruit consumption had significant interaction with residing near heavy traffic on allergy-like symptoms among children (p = 0.036). However, no association was observed by frequency of fruit consumption. Although no significant interaction was observed, we found that students with infrequent fruit consumption and residing near heavy traffic roads had elevated odds of asthma-like (POR 6.37; 95% CI 1.22, 33.29) and flu-like symptoms (POR 3.75; 95% CI 1.12, 11.86) than those who frequently consumed fruits. Likewise, low vegetable consumption was associated with increased asthma-like symptoms (POR 2.93; 95% CI 1.04, 8.24). Increased odds of asthma-like symptoms were observed among school children that resided near heavy traffic roads and frequently consumed milk (POR 2.80; 95% CI 1.24, 6.31) and yoghurt (POR 2.86; 95% CI 1.05, 7.75) compared to those that infrequently consumed dairy. Our findings suggest that frequent fruit and vegetable consumption may mitigate the negative effects of exposure to heavy traffic near dwelling on respiratory symptoms in Romanian children.

Assessment of formaldehyde levels in relation to respiratory and allergic symptoms in children from Alba County schools, Romania.

Our study assessed the exposure to formaldehyde of Romanian school children in relation to the classroom indoor environment characteristics and respiratory and allergic symptoms reported in a questionnaire survey, using the data collected in the SINPHONIE (Schools Indoor Pollution and Health: Observatory Network in Europe) project. Measurements of formaldehyde and microclimate parameters were conducted in three classrooms per school, in five schools, together with one outdoor measurement at each school. Questionnaires were used to collect information on classroom characteristics and health effects among children. The indoor formaldehyde levels for a school week varied between 15.5 and 66.2 µg/m3, with a median value of 34.8 µg/m3. The adjusted odds ratios for allergy-like, asthma-like, and flu-like symptoms were 3.23 (95% CI 1.31-8.00), 2.69 (95% CI 1.04-6.97), and 2.39 (95% CI 1.04-5.50), respectively, when exposed to higher formaldehyde levels (≥ 35 µg/m3) during a school week, compared to lower formaldehyde level exposure (< 35 µg/m3). Higher levels of indoor formaldehyde were significantly associated with health symptoms in children. The high indoor formaldehyde levels were related to the use of water-resistant paint for ceiling coverings, moisture damage signs, and lower classroom natural ventilation rates.

Agreement between parental and student reports on respiratory symptoms and school environment in young Romanian children - evidence from the SINPHONIE project.

Background Environmental research involving children often relies on the self-report or parental report of symptoms and environmental issues. While previous studies explored the agreements between child and parental reports, few of them were conducted in younger children and in developing countries. In this study, we addressed the research gaps by assessing the agreement between child and parental report on respiratory symptoms and school environment in Romanian primary schools. Methods Two hundred and eighty students from five schools and their parents participated in this study. Information on child's respiratory symptoms and perceptions of school environment was collected via both student and parent questionnaires. Agreement between the two questionnaires was assessed by absolute agreement rates and kappa statistics. Prevalence index (PI), bias index (BI) and maximum attainable kappas were calculated to identify potential sources of disagreements. Results The agreement between student and parent questionnaires was low. Compared to the student's report, parents often reported more symptoms than their children, particularly flu-like symptoms, and school environment problems. Parent and child tend to agree when there was no symptom reported, but disagreements often occurred when symptoms were reported. After adjusting for the PI, the agreements for asthma and allergic symptoms improved substantially. Disagreement on reporting of flu-like symptoms was strongly affected by pre-existing causes, such as different understandings of the questions between students and parents. Conclusion Parental report may have a higher sensitivity in capturing a child's respiratory symptoms and school environment problems compared to self-report among young children in developing countries.

Monitoring and assessment of formaldehyde levels in residential areas from two cities in Romania.

Formaldehyde has become a ubiquitous contaminant in the air, and people are exposed to it worldwide. However, few studies have evaluated the temporal-spatial levels/changes of formaldehyde exposure at residences, and the relationship between its outdoor and indoor levels has been rarely examined. The aim of this study was to assess community formaldehyde exposure in Sebes and Aiud, Romania to identify: (1) home environment characteristics that may play an important role in exposure; and understand: (2) if there were differences in formaldehyde levels between the two cities; (3) if there were temporal variations within each city; and (4) whether outdoor formaldehyde levels influence indoor levels. We simultaneously performed indoor and outdoor active air sampling for formaldehyde at each investigated residential location over a 3-year period and analyzed the samples by gas chromatography with flame ionization detector (GC-FID). The mean values of indoor and outdoor formaldehyde levels in both cities fell in the range 0.014-0.035 mg/m3. The correlation analysis indicated mostly positive but not significant (p > 0.05) correlations between indoor formaldehyde and microclimate factors (temperature, humidity, pressure). Notably, home insulation was found to be significantly correlated with increased indoor formaldehyde levels. There were no significant differences in mean indoor or outdoor formaldehyde levels between Sebes and Aiud over the 3-year study period. When comparing the formaldehyde levels in both cities over the 3-year period, only outdoor formaldehyde levels were significantly higher in 2016, as compared to those in 2017 and 2018.

Assessment of heavy metals (total chromium, lead, and manganese) contamination of residential soil and homegrown vegetables near a former chemical manufacturing facility in Tarnaveni, Romania.

Our aim was to assess local population exposure to heavy metals resulting from soil and vegetable contamination in Tarnaveni, Romania, an area located near a former chemical factory. We collected residential soil and vegetable samples from Tarnaveni and measured chromium (Cr), lead (Pb), and manganese (Mn) levels by atomic absorption spectrometry. We evaluated the relationship between soil and vegetable metals and the distance from the shuttered chemical factory, and calculated the hazard index to assess local population metal exposure via contaminated vegetable ingestion. Soil metal concentrations ranged between 15.6 and 525.8 mg/kg for total Cr, between 25.4 and 559.5 mg/kg for Pb, and between 363.1 and 1389.6 mg/kg for Mn. We found average concentrations of 17.8 mg/kg for total Cr, 2.2 mg/kg for Pb, and 116.6 mg/kg for Mn in local vegetables. We found soil concentrations for all three metals that exceeded normal background levels according to Romanian regulations (Pb exceeded 100 mg/kg in some of the samples), as well as measurable concentrations of metals in all analyzed vegetable samples. These preliminary data underscore a need for a more extensive investigation into associated adverse health effects in the exposed population.

Assessing associations between indoor environment and health symptoms in Romanian school children: an analysis of data from the SINPHONIE project.

School environment may have an impact on children's health, but few studies have focused on indoor comfort factors such as temperature, humidity, and noise in relation with potential effects on children's health. Our cross-sectional study used data from the European Schools Indoor Pollution and Health Observatory Network in Europe (SINPHONIE) project to assess children's allergy, asthma-like symptoms, and flu-like symptoms in relation with classroom comfort and environmental factors. The study used self-reported data from three questionnaires to identify classroom conditions and student health outcomes for 280 students. We used backwards variable selection and unconditional logistic regression to assess the outcome-environment relationship while controlling for demographics, family history of allergy, and home exposures. We found increased risks for allergy and flu-like symptoms associated with hot classrooms in the heating season, increased risks for asthma-like symptoms associated with noisy classrooms, and a protective effect for allergy associated with good outdoor air quality. Romanian classrooms rely on natural ventilation, which may contribute to increased temperature and humidity in the heating season. Further research warrants the use of SINPHONIE's measurement data to validate our findings.

Evidence from SINPHONIE project: Impact of home environmental exposures on respiratory health among school-age children in Romania.

BACKGROUND: Exposure to indoor air pollutants at home was found to be associated with respiratory diseases. As lifestyle changes with rapid economic growth in Romania, the aim of our study is to describe the characteristics of Romanian homes and their impact on children's respiratory health. METHODS: Self-reported information on respiratory symptoms was collected from 280 Romanian elementary school students in 2011, and the symptoms were categorized into allergy, asthma-like, and flu-like symptoms. Home characteristics and demographic information were collected from questionnaires answered by parents. The association between home characteristics and respiratory health was assessed through multivariate logistic regression controlling for school indoor exposure. RESULTS: As compared to U.S. households, Romanian homes have a higher percentage of smokers, limited use of indoor climate control, and higher use of iron stoves. Exposure to environmental tobacco smoke was associated with both asthma and allergy symptoms. Additional risk factors identified for allergy symptoms include living in apartments, near pesticide sprayed areas, and the use of incense sticks. The significantly higher risk of flu-like symptoms was associated with mold and dampness issues, the use of air conditioner, gas heater/iron stove in children's bedroom. CONCLUSION: Our findings suggest that an increase in respiratory symptoms among Romanian school-age children can be partly related to their environmental exposure at home. Since most of the identified risk factors are preventable, our results provide critical information and evidence for policymakers, to develop target intervention and education strategies.

Teacher respiratory health symptoms in relation to school and home environment.

PURPOSE: Few studies have evaluated teachers' respiratory health, especially its relationship with school/home environment, and school policies. This study assessed asthma and smoking prevalence among teachers in Romania, teacher's perception and knowledge of the school environment, policies and asthma management, and how school and home environment affected asthma, allergy, and respiratory infection symptoms. METHODS: This cross-sectional study obtained information from 104 Romanian teachers utilizing teacher questionnaire data for Romania only, as part of the Schools Indoor Pollution and Health: Observatory Network in Europe (SINPHONIE) study, a multicenter European research project conducted between 2010 and 2012. The SINPHONIE questionnaire collected comprehensive information on school and home environment, respiratory symptoms, smoking, and school policies. We used unconditional logistic regression analysis to examine environment-outcome relationships while controlling for socio-demographics and co-exposures. RESULTS: Our results showed the prevalence of asthma-like symptoms and smoking among teachers in Romania was higher than in other SINPHONIE schools and among US teachers. Factors statistically associated with asthma, allergy, and respiratory infection (all p < 0.05) include perception of health related to poor air quality in school, inappropriate cleaning of ventilation systems, dwelling proximity to busy traffic, and multiple school/home exposures. We also found lack of asthma management and environmental policies in the investigated Romanian schools. CONCLUSION: We concluded that multiple school and home environmental factors were related to respiratory and allergic symptoms. High asthma burden and smoking are important public health problems in Romania. Future studies including larger sample size and exposure measurements are needed to confirm our findings.

Low-level arsenic exposure via drinking water consumption and female fecundity - A preliminary investigation.

High level arsenic exposure is associated with reproductive toxicity in experimental and observational studies; however, few data exist to assess risks at low levels. Even less data are available to evaluate the impact of low level arsenic exposure on human fecundity. Our aim in this pilot study was a preliminary evaluation of associations between low level drinking water arsenic contamination and female fecundity. This retrospective study was conducted among women previously recruited to a hospital-based case-control study of spontaneous pregnancy loss in Timis County, Romania. Women (n=94) with planned pregnancies of 5-20 weeks gestation completed a comprehensive physician-administered study questionnaire and reported the number of menstrual cycles attempting to conceive as the time to pregnancy (TTP). Drinking water samples were collected from residential drinking water sources and we determined arsenic levels using hydride generation-atomic absorption spectrometry (HG-AAS). Multivariable Cox-proportional hazards regression with Efron approximation was employed to evaluate TTP as a function of drinking water arsenic concentrations among planned pregnancies, adjusted for covariates. There was no main effect for drinking water arsenic exposure, yet the conditional probability for pregnancy was modestly lower among arsenic exposed women with longer TTPs, relative to women with shorter TTPs, and relative to unexposed women. For example, 1µg/L average drinking water arsenic conferred 5%, 8%, and 10% lower likelihoods for pregnancy in the 6th, 9th, and 12th cycles, respectively (P=0.01). While preliminary, our results suggest that low level arsenic contamination in residential drinking water sources may further impair fecundity among women with longer waiting times; however, this hypothesis requires confirmation by a future, more definitive study.

Metal contamination in environmental media in residential areas around Romanian mining sites.

Hard-rock mining for metals, such as gold, silver, copper, zinc, iron and others, is recognized to have a significant impact on the environmental media, soil and water, in particular. Toxic contaminants released from mine waste to surface water and groundwater is the primary concern, but human exposure to soil contaminants either directly, via inhalation of airborne dust particles, or indirectly, via food chain (ingestion of animal products and/or vegetables grown in contaminated areas), is also, significant. In this research, we analyzed data collected in 2007, as part of a larger environmental study performed in the Rosia Montana area in Transylvania, to provide the Romanian governmental authorities with data on the levels of metal contamination in environmental media from this historical mining area. The data were also considered in policy decision to address mining-related environmental concerns in the area. We examined soil and water data collected from residential areas near the mining sites to determine relationships among metals analyzed in these different environmental media, using the correlation procedure in the SAS statistical software. Results for residential soil and water analysis indicate that the average values for arsenic (As) (85 mg/kg), cadmium (Cd) (3.2 mg/kg), mercury (Hg) (2.3 mg/kg) and lead (Pb) (92 mg/kg) exceeded the Romanian regulatory exposure levels [the intervention thresholds for residential soil in case of As (25 mg/kg) and Hg (2 mg/kg), and the alert thresholds in case of Pb (50 mg/kg) and Cd (3 mg/kg)]. Average metal concentrations in drinking water did not exceed the maximum contaminant level (MCL) imposed by the Romanian legislation, but high metal concentrations were found in surface water from Rosia creek, downstream from the former mining area.

Impact of exposure to tobacco smoke, arsenic, and phthalates on locally advanced cervical cancer treatment-preliminary results.

BACKGROUND: Cancer research is a national and international priority, with the efficiency and effectiveness of current anti-tumor therapies being one of the major challenges with which physicians are faced. OBJECTIVE: To assess the impact of exposure to tobacco smoke, arsenic, and phthalates on cervical cancer treatment. METHODS: We investigated 37 patients with locally advanced cervical carcinoma who underwent chemotherapy and radiotherapy. We determined cotinine and five phthalate metabolites in urine samples collected prior to cancer treatment, by gas chromatography coupled to mass spectrometry, and urinary total arsenic by atomic absorption spectrometry with hydride generation. We used linear regression to evaluate the effects of cotinine, arsenic, and phthalates on the change in tumor size after treatment, adjusted for confounding variables. RESULTS: We detected no significant associations between urinary cotinine, arsenic, or phthalate monoesters on change in tumor size after treatment, adjusted for urine creatinine, age, baseline tumor size, and cotinine (for arsenic and phthalates). However, higher %mono-ethylhexyl phthalate (%MEHP), a putative indicator of phthalate diester metabolism, was associated with a larger change in tumor size (ß = 0.015, 95% CI [0.003-0.03], P = 0.019). CONCLUSION: We found no statistically significant association between the urinary levels of arsenic, cotinine, and phthalates metabolites and the response to cervical cancer treatment as measured by the change in tumor size. Still, our results suggested that phthalates metabolism may be associated with response to treatment for locally advanced cervical cancer. However, these observations are preliminary and will require confirmation in a larger, more definitive investigation.

Low level arsenic contaminated water consumption and birth outcomes in Romania-An exploratory study.

Women are exposed to drinking water with low arsenic concentrations (<10.0µg/L) worldwide, yet little work has been done to assess the risk. To begin to address this data gap, we conducted an exploratory study of birth outcomes in Timis County, Romania. We prospectively followed 122 women with singleton deliveries, for whom we constructed individual exposure indicators using self-reported water consumption weighted by arsenic measured in drinking water sources. There were no overall confounder-adjusted effects for arsenic exposure on birth outcomes. Yet, higher average arsenic (10µg/L) was associated with a -2.45 lower birth weight Z-score (P=0.021) and a -1.17 shorter birth length Z-score (P=0.029) among smokers. Higher average iAs (10µg/L) was also associated with smaller ponderal index in boys (P=0.023). Our results suggest smoking may potentiate an otherwise benign arsenic exposure. A larger, more definitive biomarker-based study is needed to investigate the potential risks in conjunction with smoking.

A pilot study of low-moderate drinking water arsenic contamination and chronic diseases among reproductive age women in Timis County, Romania.

We conducted a pilot study of associations between drinking water contaminated by inorganic arsenic (iAs), mostly <10 µg/L, and self-reported chronic diseases in 297 pregnant women. Adjusted for confounding variables, we identified a positive association between iAs and heart disease (OR = 1.63, 95%CI 0.81-3.04, p = 0.094), which was stronger for women living at their current residence ≥ 10 years (OR = 2.47, 95%CI 0.87-10.43, p = 0.058). Confounder-adjusted associations were also suggested for iAs with kidney disease (OR = 1.32, 95%CI 0.77-2.21, p = 0.265) and with high blood pressure (OR = 1.36, 95%CI 0.68-2.39, p = 0.300). A post hoc power analysis indicated the need for a larger study with more statistical power.

Consumption of arsenic-contaminated drinking water and anemia among pregnant and non-pregnant women in northwestern Romania.

Anemia is a global health problem. To evaluate the impact of low-moderate water arsenic exposure (mostly <10 µg/L) on anemia, we conducted a cross-sectional study of 217 Romanian women. The adjusted prevalences for 'any' anemia (prevalence proportion ratio (PPR)=1.71, 95% CI 0.75-3.88) and pregnancy anemia (PPR=2.87, 95% CI 0.62-13.26) were higher among drinking water arsenic exposed women than among unexposed women. These preliminary data underscore the need for a more definitive study in this area.

Consumption of low-moderate level arsenic contaminated water does not increase spontaneous pregnancy loss: a case control study.

BACKGROUND: Previous work suggests an increased risk for spontaneous pregnancy loss linked to high levels of inorganic arsenic (iAs) in drinking water sources (>10 µg/L). However, there has been little focus to date on the impact of low-moderate levels of iAs in drinking water (<10 µg/L). To address this data gap we conducted a hospital-based case-control study in Timis County, Romania. METHODS: We recruited women with incident spontaneous pregnancy loss of 5-20 weeks completed gestation as cases (n = 150), and women with ongoing pregnancies matched by gestational age (±1 week) as controls (n = 150). Participants completed a physician-administered questionnaire and we collected water samples from residential drinking sources. We reconstructed residential drinking water exposure histories using questionnaire data weighted by iAs determined using hydride generation-atomic absorption spectrometry (HG-AAS). Logistic regression models were used to generate odds ratios (OR) and 95% confidence intervals (CI) for associations between iAs exposure and loss, conditioned on gestational age and adjusted for maternal age, cigarette smoking, education and prenatal vitamin use. We explored potential interactions in a second set of models. RESULTS: Drinking water arsenic concentrations ranged from 0.0 to 175.1 µg/L, with median 0.4 µg/L and 90th%tile 9.4 µg/L. There were no statistically significant associations between loss and average or peak drinking water iAs concentrations (OR 0.98, 95% CI 0.96-1.01), or for daily iAs intake (OR 1.00, 95% CI 0.98-1.02). We detected modest evidence for an interaction between average iAs concentration and cigarette smoking during pregnancy (P = 0.057) and for daily iAs exposure and prenatal vitamin use (P = 0.085). CONCLUSIONS: These results suggest no increased risk for spontaneous pregnancy loss in association with low to moderate level drinking water iAs exposure. Though imprecise, our data also raise the possibility for increased risk among cigarette smokers. Given the low exposures overall, these data should reassure pregnant women and policy makers with regard to the potential effect of drinking water iAs on early pregnancy, though a larger more definitive study to investigate the potential risk increase in conjunction with cigarette smoking is merited.