The impacts of Marcellus Shale gas drilling accidents on amphibians in a Pennsylvania fen

Wetlands Ecology and Management - Gas drilling into the Marcellus Shale play has been linked to environmental issues, including potential impacts on wildlife. In 2009, three separate accidents...     

Perinatal Outcomes and Unconventional Natural Gas Operations in Southwest Pennsylvania

Unconventional gas drilling (UGD) has enabled extraordinarily rapid growth in the extraction of natural gas. Despite frequently expressed public concern, human health studies have not kept pace. We investigated the association of proximity to UGD in the Marcellus Shale formation and perinatal outcomes in a retrospective cohort study of 15,451 live births in Southwest Pennsylvania from 2007–2010. Mothers were categorized into exposure quartiles based on inverse distance weighted (IDW) well count; least exposed mothers (first quartile) had an IDW well count less than 0.87 wells per mile, while the most exposed (fourth quartile) had 6.00 wells or greater per mile. Multivariate linear (birth weight) or logistical (small for gestational age (SGA) and prematurity) regression analyses, accounting for differences in maternal and child risk factors, were performed. There was no significant association of proximity and density of UGD with prematurity. Comparison of the most to least exposed, however, revealed lower birth weight (3323 ± 558 vs 3344 ± 544 g) and a higher incidence of SGA (6.5 vs 4.8%, respectively; odds ratio: 1.34; 95% confidence interval: 1.10–1.63). While the clinical significance of the differences in birth weight among the exposure groups is unclear, the present findings further emphasize the need for larger studies, in regio-specific fashion, with more precise characterization of exposure over an extended period of time to evaluate the potential public health significance of UGD.     

Are There Health Risks from the Migration of Chemical Substances from Plastic Pipes into Drinking Water? A Review

Plastic pipes used to convey hot and cold drinking water are synthetic polymers containing numerous additives that enhance durability, impact strength, and toughness, and resist material degradation. Although some research studies have been conducted to evaluate the type and levels of chemical substances migrating from polymeric materials into drinking water, the potential adverse health effects associated with these compounds in potable water have not been described. This review evaluates the literature on the occurrence of regulated and unregulated substances in drinking water related to the use of plastic pipes, characterizes potential health hazards, and describes uncertainties associated with human health and exposure in need of further research. Of particular public health concern is the potential for sensitive populations to be exposed to short-term elevations in leachates during critical periods, and for co-occurring leachates targeting the same organ(s) and/or sharing a common mode of toxic action to have additive or synergistic effects. Contaminants are measured in the distribution system, not at the tap where human exposure actually occurs. For increased health protection, it is important to identify compounds that migrate from plastic pipes into drinking water and to better quantify human exposures and health hazards to these substances and their degradates.     

A risk assessment approach for fresh fruits

Aims:  To describe the approach used in conducting a fit‐for‐purpose risk assessment of microbiological human pathogens associated with fresh fruit and the risk management recommendations made. Methods and Results:  A qualitative risk assessment for microbiological hazards in fresh fruit was carried out based on the Codex Alimentarius (Codex) framework, modified to consider multiple hazards and all fresh (whole) fruits. The assessment determines 14 significant bacterial, viral, protozoal and nematodal hazards associated with fresh produce, assesses the probable level of exposure from fresh fruit, concludes on the risk from each hazard, and considers and recommends risk management actions. A review of potential risk management options allowed the comparison of effectiveness with the potential exposure to each hazard. Conclusions:  Washing to a recommended protocol is an appropriate risk management action for the vast majority of consumption events, particularly when good agricultural and hygienic practices are followed and with the addition of refrigerated storage for low acid fruit. Additional safeguards are recommended for aggregate fruits with respect to the risk from protozoa. Significance and Impact of the Study:  The potentially complex process of assessing the risks of multiple hazards in multiple but similar commodities can be simplified in a qualitative assessment approach that employs the Codex methodology.     

Attributable risk function in the proportional hazards model for censored time-to-event

Time-to-event endpoints are often used in clinical and epidemiological studies to evaluate disease association with hazardous exposures. In the statistical literature of time-to-event analysis, such association is usually measured by the hazard ratio in the proportional hazards model. In public health, it is also of important interest to assess the excess risk attributable to an exposure in a given population. In this article, we extend the notion of 'population attributable fraction' for the binary outcomes to the attributable risk function for the event times in prospective studies. A simple estimator of the time-varying attributable risk function is proposed under the proportional hazards model. Its inference procedures are established. Monte-Carlo simulation studies are conducted to evaluate its validity and performance. The proposed methodology is motivated and demonstrated by the data collected in a multicenter acquired immunodeficiency syndrome (AIDS) cohort study to estimate the attributable risk of human immunodeficiency virus type 1 (HIV-1) infections due to several potential risk factors.     

Addressing the environmental and health impacts of microplastics requires open collaboration between diverse sectors

Public concern over the environmental and public health impacts of the emerging contaminant class “microplastics” has recently prompted government agencies to consider mitigation efforts. Microplastics do not easily fit within traditional risk-based regulatory frameworks because their persistence and extreme diversity (of size, shape, and chemical properties associated with sorbed chemicals) result in high levels of uncertainty in hazard and exposure estimates. Due to these serious complexities, addressing microplastics’ impacts requires open collaboration between scientists, regulators, and policymakers. Here we describe ongoing international mitigation efforts, with California as a case study, and draw lessons from a similarly diverse and environmentally persistent class of emerging contaminants (per- and polyfluoroalkyl substances) that is already disrupting traditional regulatory paradigms, discuss strategies to address challenges associated with developing health-protective regulations and policies related to microplastics, and suggest ways to maximize impacts of research.

Mounting concerns regarding the deleterious effects of plastic pollution have prompted recent government mitigation efforts, but microplastics challenge traditional risk-based regulatory frameworks due to their particle properties, diverse composition and persistence. Using California as a case study, the Essay suggests strategies to address challenges with regulations, policies and research, drawing parallels with a similar class of emerging contaminants (per- and polyfluoroalkyl substances).     

沈阳某冶炼厂废弃厂区的人类健康风险评价

以沈阳某冶炼厂废弃厂区重金属污染监测为依据,采用美国环保局最新的人类健康风险评价标准方法对沈阳某冶炼厂废弃地块污染土壤进行了评价,并且假设未来该土地利用类型为工业用地(Ⅰ)或休闲用地(Ⅱ).评价结果显示:工业用地(Ⅰ)和休闲用地(Ⅱ)的累积非致癌风险指数分别为2.65×10-2和3.67×10-2;工业用地(Ⅰ)和休闲用地(Ⅱ)由呼吸摄入Cd造成的潜在致癌风险指数分别为4.48×10-9和7.30×10-10,不会对在该地区工作和休闲的人们造成身体健康上的伤害;无论是工业用地假设还是休闲用地假设,由无机铜造成的人类健康风险在整个风险中所占的比例最大;由美国环保局的人类健康风险评价方法反推得出的冶炼厂地块未来为工业用地的土壤修复目标值均小于我国工业企业土壤环境质量风险评价基准值.     

Assessing Children's Exposures and Risks to Drinking Water Contaminants: A Manganese Case Study

Background: Compared to adults, children maybe more highly exposed to toxic substances in drinking water because they consume more water per unit of body weight. The U.S. Environmental Protection Agency (USEPA) has developed new guidance for selecting age groups and age-specific exposure factors for assessing children's exposures and risks to environmental contaminants. Research Aim: To demonstrate the application and importance of applying age-specific drinking water intake rates, health reference values, and exposure scenarios when assessing drinking water exposures because these approaches illustrate the potential for greater potential for adverse health effects among children. Methods: manganese, an essential nutrient and neurotoxicant, was selected as a case study and chemical of potential concern for children's health. A screening-level risk assessment was performed using age-specific drinking water intake rates and manganese concentrations from U.S. public drinking water systems. Results: When age-specific drinking water intake rates are used to calculate dose, formula-fed infants receive the highest dose of manganese from drinking water compared to all other age groups. Estimated hazard quotients suggest adverse health effects are possible. Use of USEPA's standardized childhood age groups and childhood exposure factors significantly improves the understanding of childhood exposure and risks.     

Selecting non-target species for risk assessment of entomophagous biological control agents: Evaluation of the PRONTI decision-support tool

The release of entomophagous biological control agents can pose risks to non-target invertebrate species in the release area and beyond. Pre-release risk assessment of these agents often involves tests with non-target species; however, selecting appropriate test species can be difficult when there is a large number to choose from. The PRONTI (priority ranking of non-target invertebrates) tool has been developed to aid this selection process. This automated tool prioritises species for testing using five criteria: (1) direct and indirect hazards posed by the agent, (2) likelihood of exposure to the hazards, (3) ecological impacts that may result from that exposure, (4) species’ anthropocentric value and (5) testability. Criteria (1) and (2) produce a risk estimate that drives the ranking process. In a test of PRONTI’s ability to identify non-target species at most risk from a proposed biological control agent, we used a generalist predator already present in New Zealand, the Asian paper wasp Polistes chinensis, as if it were the agent in a hypothetical biocontrol programme aimed at lepidopteran pests in New Zealand kiwifruit orchards. A ranked list of 340 invertebrate taxa known to occur in kiwifruit orchards was produced. To validate the risk estimates for a direct attack by P. chinensis on each taxon, wasps were introduced to kiwifruit orchards and prey taxa identified. Risk estimates were accurate except where identified prey taxa had not previously been recorded from kiwifruit orchards.     

A Preliminary Energy Return on Investment Analysis of Natural Gas from the Marcellus Shale

An analysis of the energy return on investment (EROI) of natural gas obtained from horizontal, hydraulically fractured wells in the Marcellus Shale was conducted using net external energy ratio methodology and available data and estimates of energy inputs and outputs. Used as sources of input data were estimates of carbon dioxide and nitrogen oxides emitted from the gas extraction processes, as well as fuel‐use reports from industry and other sources. Estimates of quantities of materials used and the associated embodied energy as well as other energy‐using steps were also developed from available data. Total input energy was compared with the energy expected to be made available to end users of the natural gas produced from a typical Marcellus well. The analysis indicates that the EROI of a typical well is likely between 64:1 and 112:1, with a mean of approximately 85:1. This range assumes an estimated ultimate recovery (EUR) of 3.0 billion cubic feet (Bcf) per well. EROI values are directly proportionate to EUR values. If the EUR is greater or lesser than 3 Bcf, the EROI would be proportionately higher or lower. EROI is also sensitive to the energy used or embedded in gathering and transmission pipelines and associated infrastructure and energy used for their construction, energy consumed in well drilling and well completion, and energy used for wastewater treatment.     

Application of a direct toxicity assessment approach to assess the hazard of potential pesticide exposure at selected sites on the Crocodile and Magalies rivers,South Africa

The potentially hazardous effects of agricultural pesticide usage in the Crocodile (west) Marico catchment were evaluated using the Danio rerio and Daphnia pulex lethality, Selenastrum capricornutum growth inhibition and the Ames mutagenicity plate incorporation assays. Hazard assessment categories are proposed to standardise the output of the different toxicity assessments. Sites were categorised according to the toxicity hazard indicated and were related to the gradients of agricultural land-use intensity at each site. Intensive agricultural sites showed the highest effects to all tested biota. Receiving water at urban sites associated with increased nutrients and lowest pesticide usage showed few adverse effects, while the relatively unimpacted site indicated no hazard to any organism, and only a slight stimulation to algal growth. Weighted hazard scores indicated that the unimpacted sites were least hazardous, falling within a B category, the urban sites were moderately hazardous (C category), and the agricultural sites (D category) had the highest potential impacts on aquatic organisms. This study demonstrated the usefulness of using the hazard assessment approach and the role it could play in assessing site-specific potential toxicity hazards of river water impacted by agrochemicals. It can be used together with other assessment methods, such as biological indices, in a tiered approach.     

Bioaerosols from municipal and animal wastes: background and contemporary issues

Global population increases, coupled with intensive animal and livestock production practices, have resulted in the generation, accumulation, and disposal of large amounts of wastes around the world. Aerosolization of microbial pathogens, endotoxins, odors, and dust particles is an inevitable consequence of the generation and handling of waste material. Bioaerosols can be a source of microbial pathogens, endotoxins, and other allergens. Given the close proximity of population centers to concentrated animal-rearing operations and municipal treatment facilities in many parts of the world, there is concern regarding the occupational and public health impacts associated with the exposure to bioaerosols from municipal and animal wastes. Major advances have been made in our understanding of bioaerosol characteristics, identifying the hazards, and identifying possible human and animal health links with aerosolized pathogens and allergens. However, significant knowledge and technology gaps still exist. These include a lack of clear understanding of the fate and transport of bioaerosols, especially within the open environment, an inability to accurately predict the health risks associated with bioaerosolized pathogens, and a lack of standardized bioaerosol sampling protocols, and efficient samplers. This review synthesizes the information related to bioaerosols and addresses the contemporary issues associated with bioaerosols from municipal and animal wastes, with a focus on pathogens.     

Identification of Risks in the Life Cycle of Nanotechnology‐Based Products

In order to realize the projected market potential of nanotechnology, the environmental, health, and safety (EHS) uncertainties posed by a nano‐product (i.e., a nanotechnology‐enabled product) need to be characterized through the identification of risks and opportunities in early stages of product development. We present a methodology to identify risks from nano‐products using a scenario analysis approach that allows for expert elicitation on a set of preidentified use and disposal scenarios and what we have labeled “risk triggers” to obtain scores on their likelihood of occurrence and severity. Use and disposal scenarios describe product life‐cycle stages that could result in risk attributed to the nano‐product, whereas risk triggers are particular to nanoparticle properties. These are potential risks, as the risk assessment community is currently debating the specific risks attributed to nanotechnology. Through such a framework, our goal is to identify which products pose greater risks, where these risks occur in the product life cycle, and the impacts of these environmental risks on society. The comparison of risk triggers across nano‐products allows relative risk ranking on axes of exposure‐ and hazard‐related risk triggers. For the specific case of air fresheners, areas of acute risks resulted from bioavailability of nanoparticles in air release and water entrainment exposure scenarios; catalytic activity of nanoparticles in inhalation and air release exposure scenarios; the harmful effects due to the antibacterial property on useful bacteria particularly in susceptible populations; and, finally, risks from the lack of nanoparticle coating stability in air release scenarios.     

Natural hazard threats to pollinators and pollination

Natural hazards are naturally occurring physical events that can impact human welfare both directly and indirectly, via shocks to ecosystems and the services they provide. Animal‐mediated pollination is critical for sustaining agricultural economies and biodiversity, yet stands to lose both from present exposure to natural hazards, and future climate‐driven shifts in their distribution, frequency, and intensity. In contrast to the depth of knowledge available for anthropogenic‐related threats, our understanding of how naturally occurring extreme events impact pollinators and pollination has not yet been synthesized. We performed a systematic review and meta‐analysis to examine the potential impacts of natural hazards on pollinators and pollination in natural and cultivated systems. From a total of 117 studies (74% of which were observational), we found evidence of community and population‐level impacts to plants and pollinators from seven hazard types, including climatological (extreme heat, fire, drought), hydrological (flooding), meteorological (hurricanes), and geophysical (volcanic activity, tsunamis). Plant and pollinator response depended on the type of natural hazard and level of biological organization observed; 19% of cases reported no significant impact, whereas the majority of hazards held consistent negative impacts. However, the effects of fire were mixed, but taxa specific; meta‐analysis revealed that bee abundance and species richness tended to increase in response to fire, differing significantly from the mainly negative response of Lepidoptera. Building from this synthesis, we highlight important future directions for pollination‐focused natural hazard research, including the need to: (a) advance climate change research beyond static “mean‐level” changes by better incorporating “shock” events; (b) identify impacts at higher levels of organization, including ecological networks and co‐evolutionary history; and (c) address the notable gap in crop pollination services research—particularly in developing regions of the world. We conclude by discussing implications for safeguarding pollination services in the face of global climate change.     

The significance of mycotoxins in the framework of assessing workplace related risks

Mycotoxins are fungal metabolite which may in some cases exhibit a high health hazard potential. Mycotoxins can show carcinogenic, mutagenic, toxic, teratogenic or immunotoxic effects. Mycotoxin exposure in the workplace may occur through inhalation and skin contact,e.g. during occupational handling of organic matter such as livestock feed, food products, or waste. Various studies suggest that both acute and chronic effects can occur, depending at least on the exposure level. The magnitude of the potential health risks associated with a respiratory or dermal intake of mycotoxins has largely remained unclear to date. However, according to the directive 2000/54/EC on biological agents and the corresponding German Biological Agents Ordinance, employers are also required to consider the potential hazards posed by toxic effects of biological agents when assessing workplace risks. The aim of this article, therefore, is to present some basis information that should facilitate an evaluation of the significance of mycotoxins in the context of assessing workplace risks. It also provides suggestions for occupational health and safety measures.     

Indoor and outdoor levels,sources, and health risk assessment of mercury in dusts from a coal-industry city of China

To understand the mercury (Hg) pollution characteristics and health risks in indoor and outdoor dust of Huainan residential areas, 122 dust samples were collected indoors and outdoors. Average Hg contents in indoor and outdoor dusts of Huainan city were 0.321 ± 0.724 (n = 61) and 0.072 ± 0.163 (n = 61) mg/kg respectively. The average Hg content in indoor dust was characterized by PJ (Panji district) > XJJ (Xiejiaji district) > DT (Datong district) > TJA (Tianjiaan district), and in the order of PJ > DT > XJJ >TJA in outdoor dust. According to enrichment factor and geo-accumulation index, the enrichment degree and pollution intensity for Hg are ranked as “very high enrichment” and “heavily polluted” in indoor dust, and “significant enrichment” and “moderately polluted” in outdoor dust Hg concentrations in indoor dust were highly significantly associated with the coal combustion and frequency of open windows, and Hg concentrations in outdoor dust were significantly associated with the coal combustion and traffic density. The inhalation of Hg vapor is the main route of Hg exposure to adult and children. The hazard risks of Hg for different exposure ways in indoor and outdoor dust were more risk for children than for adults, but have no obvious health risk for them.     

A Relative Risk Ranking of Selected Substances on Canada's National Pollutant Release Inventory

The National Pollutant Release Inventory (NPRI) provides pollutant release and transfer data from point sources to various media in the Canadian environment. While the inventory serves as Canada's community right-to-know program, the growing number of listed substances and reporting facilities makes it exceedingly difficult for the public to discern which substances are of greatest concern in their respective communities. A chemical's impact is best characterized when its environmental release data are combined with its toxicity and environmental fate properties. Presently, the NPRI does not provide a synthesis of this critical information and there is a need to provide more context with NPRI data to increase its usability. To help deliver this context, a relative risk ranking was compiled for a subset of NPRI substances using a modified Chemical Hazard and Evaluation Management Strategies (CHEMS-1) model. The model combines toxicity, chemical fate properties, and NPRI release data to yield a risk score for each substance. The resulting risk scores are ranked accordingly to provide a priority ranking of the substances. In addition to contextualizing the NPRI release data with hazard information, the ranking can also help set priorities for future risk assessment and evaluation by the Canadian government and scientific community. Limitations included the reliance on modelled data and default values to fill data gaps and uncertain reliability in reported NPRI data. In spite of its limitations, the CHEMS-1 model is a useful tool for prioritizing NPRI substances.     

Applying Mental Models to Qualitative Risk Assessment at the Tar Creek Superfund Site

Re-suspension of heavy metal residuals generated by former mining activities conducted at the Tar Creek Superfund site may result in exposures of nearby residents. Currently, remediation and mitigation activities include removal of yard soil containing high concentrations of heavy metals, removal of selected chat piles, and providing assistance for families with young children. Although these are important activities to reduce potential risks to Tar Creek residents, a qualitative assessment of the site that uses mental models identifies other potential contaminants of concern, transport, and exposure pathways that may require further investigation. Mental models structure judgments about hazards and risk by visually representing a contaminated site through the use of influence diagrams. A mental model was applied to the Mayer Ranch area of the Tar Creek Superfund site in Ottawa County, Oklahoma, to support a qualitative assessment of the health risks from heavy metals exposure. Documents were reviewed to develop influence diagrams illustrating the processes, interactions, and potential exposures that could subject a hypothetical individual recreating at Mayer Ranch to various health risks. The diagrams were modified to reflect expert judgments. The mental model includes four influence diagrams: source term, fate, and transport processes that may influence human health risks due to exposure to heavy metals; natural wetland processes that could remove heavy metals; net alkaline constructed wetland processes that could remove heavy metals; and potential future impacts from the removal of sediment and land development that could increase risk. Policies, regulations, and technologies that could most reduce the probability of exposures can be determined and evaluated by focusing on the environmental transport pathways and contaminants that pose the greatest potential risks and determining the difference between the risks. Also evident are the knowledge gaps with respect to the processes within wetlands.     

Rethinking Environmental Performance from a Public Health Perspective: A Comparative Industry Analysis

To date the most common measures of environmental performance used to compare industries, and by extension firms or facilities, have been quantity of pollution emitted or hazardous waste generated. Discharge information, however, does not necessarily capture potential health effects. We propose an alternative environmental performance measure that includes the public health risks of toxic air emissions extended to industry supply chains using economic input-output life-cycle assessment. Cancer risk to the U.S. population was determined by applying a damage function to the Toxic Release Inventory (TRI) as modeled by CalTOX, a multimedia multipathway fate and exposure model. Risks were then translated into social costs using cancer willingness to pay. For a baseline emissions year of 1998, 260 excess cancer cases were calculated for 116 TRI chemicals, dominated by ingestion risk from polycyclic aromatic compounds and dioxins emitted by the primary aluminum and cement industries, respectively. The direct emissions of a small number of industry sectors account for most of the U.S. population cancer risk. For the majority of industry sectors, however, cancer risk per $1 million output is associated with supply chain upstream emissions. Ranking industries by total (direct + upstream) supply chain risk per economic output leads to different conclusions about the relative hazards associated with these industries than a conventional ranking based on emissions per economic output.     

Heavy Metal Contamination in the Water-Level Fluctuating Zone of the Yangtze River within Wanzhou Section,China

The distribution, potential ecological hazards, and homologous relativity of heavy metals in the water-level fluctuating zone (WLFZ) of the Yangtze River within the Wanzhou Section (YRWS) were investigated. The heavy metal content (Cd, Cu, Cr, and Ni) of the surface soil was analysed via atomic absorption spectroscopy. The potential ecological hazards of the heavy metals in the WLFZ soil of YRWS were also evaluated using the classical Lars Hakanson potential ecological risk index method, and the relevance of the heavy metals in the soil was investigated. The average Cd, Cr, Cu, and Ni concentrations were 2.14, 35.43, 18.47, and 34.52 mg/kg, respectively. The Cd and Ni contents in the soil exceeded the reference values in China by about 28.6- and 1.1-fold, respectively. Correlation analysis shows a highly significant correlation between Cd and Cr, indicating that their sources were the same. The major pollutant was Cd, which reached a very strong ecological hazard level. The potential ecological risk individual coefficients of the four heavy metals were ranked as follows: Cd (802.61) > Cu (4.43) > Ni (4.15) > Cr (1.23). The risk levels in the different regions were ranked as follows: Zhuxi River > mainstream > Mixi valley. The potential ecological risk in the WLFZ within the Zhuxi River was the highest among the regions and poses a certain health risk.