Measured and Modeled Comparisons of Chemical and Microbial Contaminants in Tap and Bottled Water in a US-Mexico Border Community.

Tap water quality concerns and advertisements often drive increased bottled water consumption, especially in communities with historical tap water quality problems (e.g., Nogales, Arizona). The study objective was to assess contamination of municipal tap and bottled water in Nogales, Arizona. Bottled (sealed, open/partially consumed bottles, and reusable containers for vended water) and tap water samples were collected from 30 homes and analyzed for chemical and microbial contaminants. Fisher exact tests and Wilcoxon rank sum tests were used to compare proportions of positive samples and contaminant concentrations between tap and bottled water samples. While none of the chemical contaminants were above MCLs, there were statistically significantly greater concentrations and proportions of positive samples for some contaminants, including arsenic, in tap vs. bottled water. E. coli concentrations were >0 CFU/100mL in some unsealed bottled water samples but not for sealed bottles. This study demonstrates that 1) the measured concentrations in tap and bottled water likely pose low risks, as they are below the MCLs, 2) more education in this community on hygiene maintenance of refillable or opened bottled water containers is needed, and 3) using tap water over bottled water is advantageous due to likely lower E. coli risk and lower cost.

Inflammation biomarkers associated with arsenic exposure by drinking water and respiratory outcomes in indigenous children from three Yaqui villages in southern Sonora, México.

Environmental arsenic exposure in adults and children has been associated with a reduction in the expression of club cell secretory protein (CC16) and an increase in the expression of matrix metalloproteinase-9 (MMP-9), both biomarkers of lung inflammation and negative respiratory outcomes. The objectives of this study were to determine if the levels of serum CC16 and MMP-9 and subsequent respiratory infections in children are associated with the ingestion of arsenic by drinking water. This cross-sectional study included 216 children from three Yaqui villages, Potam, Vicam, and Cocorit, with levels of arsenic in their ground water of 70.01 ± 21.85, 23.3 ± 9.99, and 11.8 ± 4.42 µg/L respectively. Total arsenic in water and urine samples was determined by inductively coupled plasma/optical emission spectrometry. Serum was analyzed for CC16 and MMP-9 using ELISA. The children had an average urinary arsenic of 79.39 µg/L and 46.8 % had levels above of the national concern value of 50 µg/L. Increased arsenic concentrations in drinking water and average daily arsenic intake by water were associated with decreased serum CC16 levels (ß = - 0.12, 95% CI - 0.20, - 0.04 and ß = - 0.10, 95% CI - 0.18, - 0.03), and increased serum MMP-9 levels (ß = 0.35, 95% CI 0.22, 0.48 and ß = 0.29, 95% CI 0.18, 0.40) at significant levels (P < 0.05). However, no association was found between levels of these serum biomarkers and urinary arsenic concentrations. In these children, reduced serum CC16 levels were significantly associated with increased risk of respiratory infections (OR = 0.34, 95% CI 0.13, 0.90). In conclusion, altered levels of serum CC16 and MMP-9 in the children may be due to the toxic effects of arsenic exposure through drinking water.

Evaluation of Interventions to Reduce Firefighter Exposures.

OBJECTIVE: Evaluate the effectiveness of firefighter exposure reduction interventions. METHODS: Fireground interventions included use of self-contained breathing apparatus by engineers, entry team wash down, contaminated equipment isolation, and personnel showering and washing of gear upon return to station. Urinary polycyclic aromatic hydrocarbon metabolites (PAH-OHs) were measured after structural fire responses before and after intervention implementation. Separately, infrared sauna use following live-fire training was compared to standard postfire care in a randomized trial. RESULTS: The fireground interventions significantly reduced mean total urinary postfire PAH-OHs in engineers (-40.4%, 95%CI -63.9%, -2.3%) and firefighters (-36.2%, 95%CI -56.7%, -6.0%) but not captains (-11.3% 95%CI -39.4%, 29.9%). Sauna treatment non-significantly reduced total mean PAH-OHs by -43.5% (95%CI -68.8%, 2.2%). CONCLUSIONS: The selected fireground interventions reduced urinary PAH-OHs in engineers and firefighters. Further evaluation of infrared sauna treatment is needed.

Serum matrix metalloproteinase-9 in children exposed to arsenic from playground dust at elementary schools in Hermosillo, Sonora, Mexico.

Arsenic exposure in adults has been associated with increased serum matrix metalloproteinase-9 (MMP-9), a biomarker which is associated with chronic respiratory disease, lung inflammation, cardiovascular disease and cancer. The objective of this study was to evaluate the association between serum MMP-9 levels in children, urinary arsenic, arsenic chronic daily intake (CDI) and arsenic exposure from playground dust. This cross-sectional study examined 127 children from five elementary schools, in Hermosillo, Sonora, Mexico. Arsenic was analyzed in the dust using a portable X-ray fluorescence (XRF) analyzer. Total urinary arsenic was determined by inductively coupled plasma/optical emission spectrometry. Serum was analyzed for MMP-9 using ELISA. Arsenic levels in playground dust averaged 16.9 ± 4.6 mg/kg. Urinary arsenic averaged 34.9 ± 17.1 µg/L. Arsenic concentration in playground dust was positively associated with serum MMP-9 levels in crude analyses and after adjustment (P < 0.01), MMP-9 and CDI were positively associated only after adjustment (P < 0.01), and no association was found between MMP-9 and urinary arsenic. In conclusion, our study showed an association in children between serum MMP-9 levels and playground dust arsenic concentrations. Therefore, exposure to arsenic in dust where children spend significant time may manifest toxic effects.

The Donora Smog Revisited: 70 Years After the Event That Inspired the Clean Air Act.

At a storefront museum approximately 25 miles southeast of Pittsburgh, Pennsylvania, a sign reads, "Clean Air Started Here." This is not hyperbole. At the end of October 1948, the communities of Donora and Webster in Pennsylvania were visited by a smog that changed the face of environmental protection in the United States. Conservative estimates showed that 20 individuals died, while an additional 5900-43% of the population of Donora-were affected by the smog. This event led to the first large-scale epidemiological investigation of an environmental health disaster in the United States. Questions remain about the long-term effects of the smog, because higher rates of cardiovascular disease and cancer than were expected were observed in the region in the decade following the smog. Recent work has suggested that environmental contaminants from a bygone era in Donora might have an impact even today. In addition, reports regarding air pollution have indicated that levels of pollutants similar to those estimated to have occurred in Donora are currently present in some rapidly industrializing regions of China and India. Seventy years after the smog, this event still resonates.

Binational arsenic exposure survey: methodology and estimated arsenic intake from drinking water and urinary arsenic concentrations.

The Binational Arsenic Exposure Survey (BAsES) was designed to evaluate probable arsenic exposures in selected areas of southern Arizona and northern Mexico, two regions with known elevated levels of arsenic in groundwater reserves. This paper describes the methodology of BAsES and the relationship between estimated arsenic intake from beverages and arsenic output in urine. Households from eight communities were selected for their varying groundwater arsenic concentrations in Arizona, USA and Sonora, Mexico. Adults responded to questionnaires and provided dietary information. A first morning urine void and water from all household drinking sources were collected. Associations between urinary arsenic concentration (total, organic, inorganic) and estimated level of arsenic consumed from water and other beverages were evaluated through crude associations and by random effects models. Median estimated total arsenic intake from beverages among participants from Arizona communities ranged from 1.7 to 14.1 µg/day compared to 0.6 to 3.4 µg/day among those from Mexico communities. In contrast, median urinary inorganic arsenic concentrations were greatest among participants from Hermosillo, Mexico (6.2 µg/L) whereas a high of 2.0 µg/L was found among participants from Ajo, Arizona. Estimated arsenic intake from drinking water was associated with urinary total arsenic concentration (p < 0.001), urinary inorganic arsenic concentration (p < 0.001), and urinary sum of species (p < 0.001). Urinary arsenic concentrations increased between 7% and 12% for each one percent increase in arsenic consumed from drinking water. Variability in arsenic intake from beverages and urinary arsenic output yielded counter intuitive results. Estimated intake of arsenic from all beverages was greatest among Arizonans yet participants in Mexico had higher urinary total and inorganic arsenic concentrations. Other contributors to urinary arsenic concentrations should be evaluated.

Environmental Arsenic Exposure and Urinary 8-OHdG in Arizona and Sonora.

Although at high levels arsenic exposure is associated with increased cancer incidence, information on the health effects of lower exposure levels is limited. The objective of this study was to determine whether arsenic at concentrations below 40 microg/L in drinking water is associated with increased urinary 8-hydroxydeoxyguanosine (8-OHdG), a biomarker of DNA oxidative damage and repair. Urine samples were collected from 73 nonsmoking adults residing in two communities in Arizona (mean tap water arsenic (microg/L) 4.0 +/- 2.3 and 20.3 +/- 3.7), and 51 subjects in four communities in Sonora, Mexico (mean tap water arsenic (microg/L) ranging from 4.8 +/- 0.1 to 33.3 +/- 0.6). Although urinary arsenic concentration increased with higher exposure in tap water, urinary 8-OHdG concentration did not differ by community within Arizona or Sonora, and was not associated with urinary arsenic concentration. At the exposure levels evaluated in this study, drinking water arsenic was not associated with increased DNA oxidation as measured by urinary 8-OHdG.

Arsenic exposure is associated with decreased DNA repair in vitro and in individuals exposed to drinking water arsenic.

The mechanism(s) by which arsenic exposure contributes to human cancer risk is unknown ; however, several indirect cocarcinogenesis mechanisms have been proposed. Many studies support the role of As in altering one or more DNA repair processes. In the present study we used individual-level exposure data and biologic samples to investigate the effects of As exposure on nucleotide excision repair in two study populations, focusing on the excision repair cross-complement 1 (ERCC1) component. We measured drinking water, urinary, or toenail As levels and obtained cryopreserved lymphocytes of a subset of individuals enrolled in epidemiologic studies in New Hampshire (USA) and Sonora (Mexico). Additionally, in corroborative laboratory studies, we examined the effects of As on DNA repair in a cultured human cell model. Arsenic exposure was associated with decreased expression of ERCC1 in isolated lymphocytes at the mRNA and protein levels. In addition, lymphocytes from As-exposed individuals showed higher levels of DNA damage, as measured by a comet assay, both at baseline and after a 2-acetoxyacetylaminofluorene (2-AAAF) challenge. In support of the in vivo data, As exposure decreased ERCC1 mRNA expression and enhanced levels of DNA damage after a 2-AAAF challenge in cell culture. These data provide further evidence to support the ability of As to inhibit the DNA repair machinery, which is likely to enhance the genotoxicity and mutagenicity of other directly genotoxic compounds, as part of a cocarcinogenic mechanism of action.

Arsenic drinking water exposure and urinary excretion among adults in the Yaqui Valley, Sonora, Mexico.

The objective of this study was to determine arsenic exposure via drinking water and to characterize urinary arsenic excretion among adults in the Yaqui Valley, Sonora, Mexico. A cross-sectional study was conducted from July 2001 to May 2002. Study subjects were from the Yaqui Valley, Sonora, Mexico, residents of four towns with different arsenic concentrations in their drinking water. Arsenic exposure was estimated through water intake over 24 h. Arsenic excretion was assessed in the first morning void urine. Total arsenic concentrations and their species arsenate (As V), arsenite (As III), monomethyl arsenic (MMA), and dimethyl arsenic (DMA) were determined by HPLC/ICP-MS. The town of Esperanza with the highest arsenic concentration in water had the highest daily mean intake of arsenic through drinking water, the mean value was 65.5 microg/day. Positive correlation between total arsenic intake by drinking water/day and the total arsenic concentration in urine (r = 0.50, P < 0.001) was found. Arsenic excreted in urine ranged from 18.9 to 93.8 microg/L. The people from Esperanza had the highest geometric mean value of arsenic in urine, 65.1 microg/L, and it was statistically significantly different from those of the other towns (P < 0.005). DMA was the major arsenic species in urine (47.7-67.1%), followed by inorganic arsenic (16.4-25.4%), and MMA (7.5-15%). In comparison with other reports the DMA and MMA distribution was low, 47.7-55.6% and 7.5-9.7%, respectively, in the urine from the Yaqui Valley population (except the town of Cocorit). The difference in the proportion of urinary arsenic metabolites in those towns may be due to genetic polymorphisms in the As methylating enzymes of these populations.