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Managing building water systems is complicated by the need to maintain hot water temperatures high enough to control the growth of Legionella spp. while minimizing the risk of scalding. This study assessed water quality management practices in large buildings in the United States. Surveys conducted with building water quality managers found that more than 85% of buildings have hot water temperatures that are consistent with scald risk mitigation guidelines (i.e., <122 °F/50 °C). However, nearly two thirds and three quarters of buildings do not comply with the common temperature guidance for opportunistic pathogen control, i.e., water heater setpoint > 140 °F (60 °C) and recirculation loop > 122 °F (50 °C), respectively; median values for both setpoint and recirculation loop temperatures are 10 °F (6 °C) or more below temperatures recommended for opportunistic pathogen control. These observations suggest that many buildings are prone to Legionella spp. risk. The study also found that 27% of buildings do not comply with guidelines for time to equilibrium hot water temperature, over 33% fail to monitor temperature in the recirculation loop, more than 70% fail to replace or disinfect showerheads, more than 40% lack a written management plan, and only a minority conduct any monitoring of residual disinfectant levels or microbiological quality. Given the rise in Legionellosis infections in recent years, coupled with highlighted water quality concerns because of prolonged water stagnation in plumbing, such as in buildings closed due to COVID-19, current management practices, which appear to be focused on scald risk, may need to be broadened to include greater attention to control of opportunistic pathogens. To accomplish this, there is a need for formal training and resources for facility managers. [ABSTRACT FROM AUTHOR]

The article presents a study which investigates the incidence of indicator organisms and pathogens that are found in Class B biosolids across the U.S. The study involves the examination of Class B biosolids in the 21 samples of 18 wastewater plants across the country and the national and historic distribution of the incidence of bacterial and viral pathogens between 2005 and 2008. Moreover, it concludes that the promulgation of the Environmental Protection Agency (EPA) Part 503 Rule in 1993 has created a positive influence in reducing pathogen loads.

In many cases, human health risk from biological agents is associated with aerosol exposures. Because air concentrations decline rapidly after a release, it may be necessary to use concentrations found in other environmental media to infer future or past aerosol exposures. This article presents an approach for linking environmental concentrations of Bacillus. anthracis ( B. anthracis) spores on walls, floors, ventilation system filters, and in human nasal passages with human health risk from exposure to B. anthracis spores. This approach is then used to calculate example values of risk-informed concentration standards for both retrospective risk mitigation (e.g., prophylactic antibiotics) and prospective risk mitigation (e.g., environmental clean up and reoccupancy). A large number of assumptions are required to calculate these values, and the resulting values have large uncertainties associated with them. The values calculated here suggest that documenting compliance with risks in the range of 10−4 to 10−6 would be challenging for small diameter (respirable) spore particles. For less stringent risk targets and for releases of larger diameter particles (which are less respirable and hence less hazardous), environmental sampling would be more promising. [ABSTRACT FROM AUTHOR]

Although approximately 35 million people in the US obtain drinking water from domestic wells, few studies have investigated the risk of arsenic exposure from this source. In this paper arsenic concentrations were modeled for public and domestic wells using a dataset from the US Geological Survey (USGS). Excess lifetime and annual risks for lung and bladder cancer were calculated based on the carcinogenic potency and average arsenic concentrations in public and domestic water supplies. Monte Carlo uncertainty analysis was used to estimate the degree of confidence in these estimations. Results indicated that domestic well users accounted for 12% of the US population, but 23% of overall arsenic exposure from drinking water. Assuming that the new and more restrictive arsenic maximum contaminant limit (MCL) is implemented for public water supplies, it is anticipated that the proportion of people experiencing excess annual fatalities from drinking water from domestic wells will increase to 29% unless corresponding efforts are made to reduce exposures among domestic well users. Differences between public and domestic wells were not consistent across the nation. Public wells tend to tap deeper aquifers than domestic wells, and as a result local arsenic-depth trends can contribute to differences between public and domestic wells. Domestic wells and public wells in the western US have the highest arsenic levels with excess fatality risks estimated to be in the range of 1 per 9300 to 1 per 6600 in these regions. Uncertainty distributions of excess fatalities were developed and resultant uncertainties were propagated in arsenic exposure and potency factor. Uncertainty in the carcinogenic potency of arsenic was the dominant source of uncertainty in most regions, but for domestic wells in the New England and Southeast regions uncertainty in arsenic exposure was dominant, indicating that additional data on arsenic concentrations in these areas would substantially improve regional risk estimates. [ABSTRACT FROM AUTHOR]

Observations of traffic inspections at a U.S. land border port of entry in El Paso, TX indicate that the process is highly variable. In a series of 24 half-hour observation periods of ordinary noncommercial traffic, the average inspection duration ranged from 16.6 s to 56.6 s. The proportion of inspections which involved some physical search of the vehicle, as indicated by the inspector leaving the inspection booth, varied from 5% to 56% in different observation periods. In 4 out of 10 cases, the log-mean of inspection duration in simultaneous observations of parallel lanes of traffic differed significantly (p<0.05). This suggests that differences in inspector behavior are responsible for much of the variability of the inspection process. Similar results are found for the SENTRI program. A survey of public perception reveals that a majority of English-language respondents perceive the inspectors to be fair while a majority of Spanish language respondents (both U.S. and Mexican citizens) perceive the process to be more arbitrary, as they state that fairness "depends on the inspector." Spanish-language respondents are also more likely to report having to submit to additional searches than English-language respondents. A common theme that emerges from the analysis of these two datasets is that efforts to standardize some aspects of inspections, while preserving inspector autonomy, may improve the performance of the process by eliminating variability which organized criminal groups may be able to exploit. [ABSTRACT FROM AUTHOR]

The current framework for U.S. Environmental Protection Agency regulation of water quality in community drinking water supplies produces sequential rules for either single contaminants or small groups of similar contaminants. For both substantive and pragmatic reasons, some water industry experts have advocated the development of a more holistic regulatory process in which rules are promulgated less frequently but for larger contaminant classes. Such a framework would require the expansion of existing regulatory evaluation technologies to account for joint occurrence distributions of multiple contaminants. This article presents an analysis, using two national contaminant databases, of the joint distributions of seven contaminants (arsenic, nitrate, uranium, manganese, magnesium, calcium, and sulfate) in community water system source waters. Inferences are based on a flexible Bayesian hierarchical modeling structure with numerous features desirable for empirical exploration of multicontaminant regulations, including the simultaneous estimation of spatial heterogeneity in contaminant levels and covariations among contaminants, applicability to sparse data collected over a large spatial scale, and coherent assimilation of information provided by censored observations. The model is used to estimate a family of joint distributions for the contaminants indexed by water system characteristics, with empirically appropriate complexity given the resolution of the available data. The resulting distributions provide insights about the nature of, and uncertainty about, contaminant co-occurrence patterns, quantify the impact on national assessments of jointly modeling the contaminants, and facilitate identification of critical classes of water systems where uncertainty is highest. [ABSTRACT FROM AUTHOR]

Focuses on benefit-cost analyses for drinking water regulations in the U.S. Data on mean fitted interchemical correlation coefficients of raw water log concentrations within each state for groundwater; Use of a statistical simulation approach; Information on existing treatment probabilities for groundwater and surface water systems.

Examines the revision of arsenic drinking water standard in the United States. Consideration of cost in promulgating maximum contaminant level for water; Discrepancy in the cost estimates for arsenic treatment; Importance of regulatory guidance by the state.

Focuses on the correlation between diabetes prevalence and air pollution emissions in the U.S. Use of multivariate regression approach in the study; Analysis of the state level emissions data; Utilization of the data to improve health outcomes.

Background: This quantitative microbial risk assessment (QMRA) included problem formulation for fomites and hazard identification for 7 microorganisms, including pathogenic Escherichia coli and E coli 0157:H7, Listeria monocytogenes, norovirus, Pseudomonas spp, Salmonella spp, and Staphylococcus aureus. The goal was to address a risk-based process for choosing the log10 reduction recommendations, in contrast to the current US Environmental Protection Agency requirements., Method: For each microbe evaluated, the QMRA model included specific dose-response models, occurrence determination of aerobic bacteria and specific organisms on fomites, exposure assessment, risk characterization, and risk reduction. Risk estimates were determined for a simple scenario using a single touch of a contaminated surface and self-inoculation. A comparative analysis of log10 reductions, as suggested by the US Environmental Protection Agency, and the risks based on this QMRA approach was also undertaken., Results: The literature review and meta-analysis showed that aerobic bacteria were the most commonly studied on fomites, averaging 100 colony-forming units (CFU)/cm(2). Pseudomonas aeruginosa was found at a level of 3.3 × 10(-1) CFU/cm(2); methicillin-resistant S aureus (MRSA), at 6.4 × 10(-1) CFU/cm(2). Risk estimates per contact event ranged from a high of 10(-3) for norovirus to a low of 10(-9) for S aureus., Conclusion: This QMRA analysis suggests that a reduction in bacterial numbers on a fomite by 99% (2 logs) most often will reduce the risk of infection from a single contact to less than 1 in 1 million., (Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.)