Environmental Hazard Assessment Research Articles

Zn mobility and geochemistry in surface sulfide mining soils from SE Spain

The extraction of metallic minerals and the mineral dressing operations in concentrators produced a high impact in soils and sediments. Heavy metals in soils constitute a high risk of pollution, not only for mining areas, but also for agriculture and villages placed in subsidiary areas. This research has been focused on the assessment of the real environmental and health hazards of Zn in relation to geochemistry and metal mobility in surface soils from a mining area in SE Spain, under semiarid weather conditions. Mineralogy of the studied soils revealed major presence of quartz, but also of other silicates, sulfates, carbonates, and sulfides. Regarding Zn minerals, the presence of sphalerite as the main Zn sulfide, and of goslarite as Zn sulfate, and of smithsonite as Zn carbonate should be highlighted. Soil pH ranged between 4.4 and 4.9 and the electrical conductivity between 55 and 85 μS/cm. By using the sequential extraction procedure, the achieved results show that zinc is not only mainly associated to primary but also to secondary sulfides. Total concentration of the non-available fractions rises up to 98.45% of total Zn in the studied soils. On the other hand, available Zn fraction did not exceed more than 1.55% in percentage and less than 2000 ppm in absolute terms, and when referred to more easily available fraction (water-soluble and exchangeable fractions), these values are not more than 0.44% and then 800 ppm. Therefore, although there is a significant pollution level in this area, immediate hazard for the environment can be assessed as moderate. Finally it should be highlighted that these surface soils have undergone concentration processes of sphalerite, whose mechanisms should be related to the ascending flow of capillary water and the dragging of sphalerite crystals and Zn salts by electrokinetic and colloidal processes These processes seem to occur based on environmental pollution by wind and water erosion, and therefore directly associated to environmental pollution and risks by free metals.

Ranking Cancer Risks of Organic Hazardous Air Pollutants in the United States

BackgroundIn this study we compared cancer risks from organic hazardous air pollutants (HAPs) based on total personal exposure summed across different microenvironments and exposure pathways.MethodsWe developed distributions of personal exposure concentrations using field monitoring and modeling data for inhalation and, where relevant, ingestion pathways. We calculated risks for a nonoccupationally exposed and nonsmoking population using U.S. Environmental Protection Agency (EPA) and California Office of Environmental Health and Hazard Assessment (OEHHA) unit risks. We determined the contribution to risk from indoor versus outdoor sources using indoor/outdoor ratios for gaseous compounds and the infiltration factor for particle-bound compounds.ResultsWith OEHHA’s unit risks, the highest ranking compounds based on the population median are 1,3-butadiene, formaldehyde, benzene, and dioxin, with risks on the order of 10−4–10−5. The highest risk compounds with the U.S. EPA unit risks were dioxin, benzene, formaldehyde, and chloroform, with risks on a similar order of magnitude. Although indoor exposures are responsible for nearly 70% of risk using OEHHA’s unit risks, when infiltration is accounted for, inhalation of outdoor sources contributed 50% to total risk, on average. Additionally, 15% of risk resulted from exposures through food, mainly due to dioxin.ConclusionsMost of the polycyclic aromatic hydrocarbon, benzene, acetaldehyde, and 1,3-butadiene risk came from outdoor sources, whereas indoor sources were primarily responsible for chloroform, formaldehyde, and naphthalene risks. The infiltration of outdoor pollution into buildings, emissions from indoor sources, and uptake through food are all important to consider in reducing overall personal risk to HAPs.

Testing a climate erosive forcing model in the Po River Basin

Changes in the spatial and temporal features of precipitation patterns may have important effects on the magnitude and timing of erosive rainfalls, which will in turn result in changes in soil degradation response. This study presents a secular timescale environmental hazard assessment to account for the impacts of climate erosive forcing on an agricultural landscape identified as potentially vulnerable, mainly to erosional soil degradation processes. An empirical probabilistic model for temporal characterisation of this impact, termed CHIEF (Climate Hazard Index Erosive Forcing), was developed to evaluate the annual balance between climate driving and climate resisting forces in the Po River Basin (northern Italy) during the period 1775 to 2003. In the CHIEF approach, an ecological system adapted to the natural hydro-climatic regime was assumed; fluctuations in this regime, especially those exceeding thresholds of rainfall energy intensity, may trigger erosional soil degradation processes. In this way, the time sensitivity of the CHIEF model reflects the magnitude of annual input nested within patterns of long-term environmental change occurring within a specific temporal window, in order to capture different modes of climatic variability and their hydro-geomorphological implications.

Towards a golden standard for the regulatory assessment of health and environmental hazards: Part 1

We assess, in the second part of our research on the broad context of establishing a golden standard for regulatory risk assessment. The policies of international jurisdictions can (and often are) different from those in the US; yet, they are neither opposite nor inconsistent with regulating societal hazards rationally. Although rational decision-making is understood to be the normative use of economically efficient solutions, which consist of ranking alternatives by balancing risks, costs and benefits (possibly discounted, adjusted for purchasing parity and so on), we think that risk assessment is prescriptive and informative, but not necessarily normative. In Part 2, we conclude that regulatory risk management, regardless of the jurisdiction assessed, can benefit from relying on a common treatment of uncertain causation. In particular, we suggest that probabilistic methods applied from a Bayesian perspective, at least when frequentistic arguments cannot be made. Clearly, as discussed in Part 1, other representations of uncertainty can be more appropriate; however, because the courts and the legislation is still favouring probabilistic and statistical analysis when reviewing agency rules, we suggest that the prudent tack is to couch causal arguments and decision-making in probabilistic and statistical framework.

Toward a golden standard for the regulatory assessment of health and environmental hazards, part 2

Toward a golden standard for the regulatory assessment of health and environmental hazards, part 2

Risk Assessment and Epidemiologic Evidence: Kundi Responds

I appreciate Goldstein’s remarks about the role of epidemiology in risk assessment of environmental hazards and the opportunity to clarify my standpoint. With reference to the International Agency for Research on Cancer’s classification scheme of agents for their carcinogenicity in humans and other schemes such as that of the U.S. Environmental Protection Agency (EPA), Pitot and Dragan (2001) stated in Casarett and Doull’s Toxicology: In spite of the limitations of these classifications, an agent cannot be proven to be carcinogenic for the human unless substantial epidemiologic evidence supporting such a claim is available. Although this statement refers to carcinoma and not to the broader class of chronic diseases, it seems to be very close to my statement (Kundi 2006) that Goldstein criticizes. However, Goldstein particularly emphasizes that I may have meant that “there must be epidemiologic evidence for a chemical to achieve the level of a known or proven cause of a hazard to human health.” The reader may have noticed that I never used the term “proven” (Kundi 2006), and I deliberately did not. In my opinion we cannot reach the level of a proven cause. Our knowledge is always incomplete; although we may be quite sure about a factor causing a disease, it may turn out to be actually unrelated. Using toxicologic evidence, we may conjecture that an agent has a potential to cause human chronic disease, but we need further evidence—in most cases epidemiologic evidence—to establish a causal relationship between the agent and a chronic disease in humans. (I make a conceptual difference between “establishing” and “proving,” the latter defined as “establishing truth,” which can only be done for analytical statements.) My statement that Goldstein criticizes was misleading insofar as it seems to indicate that we have to start from epidemiologic evidence to ascribe an agent a hazardous potential for human health. In many cases first information on a potential hazard will stem from routine toxicologic testing. The last paragraphs of my commentary (Kundi 2006) were intended to give an outlook to future developments that may provide answers to the question of causation of chronic diseases in a more rapid fashion. From this context it should be clear that risk assessment was addressed with respect to the causal role of an agent. Therefore, a slight modification of the statement above is appropriate: An agent cannot be established to cause a chronic human disease unless supporting epidemiologic evidence is available. Among other improvements, comprehensive utilization of modern molecular biological methods integrated into epidemiologic designs may provide such evidence at an early stage of the disease.

Landform–vegetation units for investigating the dynamics and geomorphologic evolution of alpine composite debris cones (Valle dell'Avio, Adamello Group, Italy)

Cluster analysis of 245 vegetation plots, along 17 transects on alpine composite debris cones in the Italian Alps, allowed us to classify complex mosaics of landforms and plant communities. A variety of active and past geomorphic processes (mass wasting, avalanche activity, and running water) were responsible for the construction of the debris cones. By assessing plant community distribution in the context of the different landform units and geomorphic processes, represented in detailed geomorphological maps, a sequence of landform–vegetation units was identified. This approach contributes to the assessment of environmental hazards on the cones, and may also be applied in other environmental contexts. Plant community distribution and development in Valle dell'Avio reflects the frequency and intensity of the processes that built composite alpine debris cones, creating environmental gradients and/or generating new habitats. Therefore this patchy landscape allows the preservation of local biodiversity, with typical plant communities adapted to particular niches.

Field Dissipation and Environmental Hazard Assessment of Clomazone, Molinate, and Thiobencarb in Australian Rice Culture

The fates of clomazone [2-(2-chlorophenyl)methyl-4,4-dimethyl-3-isoxazolidinone], molinate (S-ethyl hexahydro-1-H-azepine-1-carbothioate), and thiobencarb {S-[(4-chlorophenyl)methyl]diethylcarbamothioate} applied to rice were studied at two locations in New South Wales (Australia). Rates of dissipation (DT50) from floodwaters and soils were measured. Dissipation of the three herbicides from water and soil can be best explained by a first-order decay process. DT(50) values for clomazone, molinate, and thiobencarb were 7.2, 5.1, and 3.5 days, respectively, in water and 14.6, 23.9, and >46 days, respectively, in surface soil. Maximum measured concentrations of clomazone, molinate, and thiobencarb in floodwaters were 202, 1042, and 148 microg/L, respectively, taking 18.4, 26.4, and 21.4 days to dissipate to concentrations set to protect aquatic ecosystems. A hazard assessment identified clomazone as presenting a low environmental hazard while molinate and thiobencarb presented a medium environmental hazard when used at registered field rates.

Environmental hazard analysis and effective remediation of highway seepage

Risk assessment and minimisation of environmental hazards are critical issues to consider in the geotechnical engineering projects. A case of highway pavement seepage induced by groundwater, at a locality along the section of Hua-Qing Highway of Guangdong Province, China, is presented for environmental hazard analysis and effective remediation. The environmental hazard analyses were based on in situ hydrogeologic investigation, rock–soil testing and integrated environmental understanding. The analyses indicate that the highway seepage was caused by elevation of groundwater hydraulic pressure in low permeable strata near the highway pavement, which was controlled by landform, hydrology, weather and road structure. The risk source of groundwater ‘flooding’ was the groundwater and surface water in the ring-like valley around Fenshui Village. A blind-ditch system for effective remediation of the pavement seepage hazard was proposed and successfully implemented by declining groundwater table near the highway based on the comprehensive assessment of various conditions. This geotechnical accident shows that the role of groundwater is an essential factor to consider in the geotechnical and environmental engineering studies and multidisciplinary effort for risk assessment of environmental hazards is important under current global climate change condition.

Factors affecting arsenic speciation in environmental samples: sample drying and storage

Arsenic is a ubiquitous element. Its toxicity, mobility, and bioaccumulation depend usually on its chemical form, and therefore, arsenic speciation is indispensable for the assessment of environmental risk and human hazard. Little is known about the effect of sample preparation procedures, such as drying and storage, on the resulting arsenic speciation. In this study, we investigated the influence of different drying methods and storage conditions on the arsenic speciation in mineral soils, organic soils, and plants. Drying soils and plants using different methods may change the concentrations of the total methanol–water (20%, v/v) extractable arsenic, the proportion of organic arsenic and the ratio of arsenite-to-arsenate. Loss of methanol–water extractable arsenic compounds (up to 63%) was observed particularly in the samples rich in water. Following drying, the speciation of organic arsenic changed less than that of inorganic arsenic. Drying showed little influence on the total arsenic determination. None of the storage methods tested could preserve the arsenic speciation in organic soils and plants, although arsenic speciation after one-month storage varied less in freeze-dried samples than wet samples. Storage of the samples at low temperatures (2 or −20°C) had the largest impact on the samples rich in organic matters, leading to less arsenic being extractable by methanol–water. Both drying and storage of the soil and plant samples changed apparently the arsenic speciation. Therefore, we recommend conducting the arsenic speciation possibly with fresh and wet samples, so that the results of arsenic speciation may be more approaching the original states.

A review of environmental hazards associated with in-patient falls

Slips, trips and falls present the greatest risk to in-patients in terms of exposure (frequency of occurrence) but only present a low severity risk in terms of mortality. The risk factors have been categorized as intrinsic (individual to the patient, e.g. visual impairment, balance problems and medicine use) or extrinsic (environmental). Many recommendations have been made concerning the management of environmental hazards but, of these, only beds rails have supporting research evidence. Other recommendations include patient assessment, footwear, flooring, lighting, staffing levels and bed alarms. However, three systematic reviews and the current narrative review have all failed to find research evaluating the benefits of these recommendations. The most robust evidence relates to the use of bed rails. This research suggests that bed rails not only fail to reduce the frequency of falls, but may also exacerbate the severity of injury. As Maslow's Hierarchy of Needs model has been used as a framework for nursing models of care, it was chosen as the basis for the development of an environmental hazard assessment model. The environmental hazards are revisited using this model in order to take an ergonomic or patient-centred approach for risk assessment.

Initial Assessment of a Forgotten Minority Community

Environmental hazards are increasingly being detected in minority and low-income communities. The Fresno, Texas community is located near Houston, Texas, and many of its residents are ethnic minorities and of low socioeconomic status. While Fresno residents have voiced concerns about long-standing undocumented environmental hazards, the extent to which the concerns were accurate was unclear. As an initial assessment of environmental exposure hazards, key informant interviews of residents and officials were conducted to examine the perceptions of environmental exposures and associated health effects in the Fresno community. The responses about perceived environmental exposures and the extent of access to primary healthcare were similar between residents and officials. The key informants identified inadequate public water supply and possible groundwater contamination as sources of potential environmental exposures and agreed that access to primary healthcare was a major problem in the Fresno area. However, Fresno residents and officials had contrasting perceptions about the overall health of the community, the existence of community-based organizations, strengths and barriers of the community, and how well environmental concerns were addressed. Qualitative methodology was used to conduct key informant interviews of seven residents and five elected or assigned officials who serve residents of Fresno. An interview guide designed to obtain information on potential environmental hazards and associated health effects was utilized to collect qualitative data that were then utilized to identify recurrent themes and dissimilarities of responses. The responses obtained in this study suggest that potential environmental exposures may be present in this community. However, although residents and officials identified access to primary healthcare as a barrier to residing in Fresno, residents and officials had differing perceptions of the overall heath status of the Fresno community. These findings must be further investigated to develop additional qualitative and quantitative studies that will validate the preliminary findings of this study and begin to accurately measure contaminant levels and health status in Fresno residents.

Assessing the aquatic hazard of commercial hydrocarbon resins

Hydrocarbon resins are used to modify polymer products to achieve desired functional properties for a diverse range of products. These complex hydrocarbon-based mixtures are typically poorly soluble in water. However, resins may leach lower-molecular-weight monomers or impurities upon contact with water, thus posing a potential hazard to the aquatic environment. The bioavailability and toxicity of leachable constituents of four solid and three liquid resins were evaluated by analyzing water-accommodated fractions prepared with each resin, using biomimetic solid phase microextraction (SPME) techniques. Liquid resins exhibited concentrations of bioavailable constituents that were sufficiently elevated to cause acute toxicity to the aquatic organism Daphnia magna. All solid resins exhibited lower bioavailable concentrations of leachable constituents that were unlikely to pose an aquatic toxicity concern. Since observed toxicity of both resin types was generally consistent with bioavailable concentrations determined using SPME fiber measurements, it is concluded that this approach provides a convenient in vitro screening tool that can help reduce the use of animal testing in environmental hazard assessment of complex hydrocarbon-based substances.

Assessment of environmental radon hazard using human respiratory tract models

Radon is a natural radioactive gas derived from geological materials. It has been estimated that about half of the total effective dose received by human beings from all sources of ionizing radiation is attributed to 222Rn and its short-lived progeny. In this paper, the use of human respiratory tract models to assess the health hazard from environmental radon is reviewed. A short history of dosimetric models for the human respiratory tract from the International Commission on Radiological Protection (ICRP) is first presented. The most important features of the newest model published by ICRP in 1994 (as ICRP Publication 66) are then described, including the morphometric model, physiological parameters, radiation biology, deposition of aerosols, clearance model and dose weighting. Comparison between different morphometric models and comparison between different deposition models are then given. Finally, the significance of various parameters in the lung model is discussed, including aerosol parameters, subject related parameters, target and cell related parameters, and parameters that define the absorption of radon from the lungs to blood. Dosimetric calculations gave a dose conversion coefficient of 15 mSv/WLM, which is higher than the value 5 mSv/WLM derived from epidemiological studies. ICRP stated that dosimetric models should only be used for comparison of doses in the human lungs resulted from different exposure conditions.

Artificial streams in the assessment of environmental hazard of chemicals

Artificial streams are dynamic mesocosms, simulating aquatic systems and rivers. They are useful to study ecotoxicity of chemicals and their effects on flora and fauna colonizing the streams or introduced into the channels. These artificial rivers can also be used to study the influence of ecological and hydrodynamic parameters, such as the kind of substrate of river and flow rate. Responses of the bivalve Unio tumidus to substrate type (silt, sand, and pebbles) and water flow rate (high and low) were investigated after 15 and 35 days in the channels, in order to optimize the experimental conditions for ecotoxicity study with methyl methacrylate (MMA). The toxicological effects of different concentrations of MMA on bivalves and on communities of invertebrates and diatoms were determined after several weeks of exposure at a high flow rate. Biomarkers responses measured in the digestive gland and the gills of U. tumidus were the activities of detoxification systems as early indicators of toxicity and lipid peroxidation as a marker of cytotoxicity. Effects of MMA resulted in a decrease in antioxidant activities. Disturbances in bivalves appeared at lower concentrations than in communities. This indicates sensitivity of the biomarkers studied, which are predictive indicators of ecotoxicity.

Are pharmaceuticals potent environmental pollutants?: Part I: Environmental risk assessments of selected active pharmaceutical ingredients

As part of achieving national environmental goals, the Swedish Government commissioned an official report from the Swedish Medical Products Agency on environmental effects of pharmaceuticals. Considering half-lives/biodegradability, environmental occurrence, and Swedish sales statistics, 27 active pharmaceutical ingredients were selected for environmental hazard and risk assessments. Although there were large data gaps for many of the compounds, nine ingredients were identified as dangerous for the aquatic environment. Only the sex hormones oestradiol and ethinyloestradiol were considered to be associated with possible aquatic environmental risks. We conclude that risk for acute toxic effects in the environment with the current use of active pharmaceutical ingredients is unlikely. Chronic environmental toxic effects, however, cannot be excluded due to lack of chronic ecotoxicity data. Measures to reduce potential environmental impact posed by pharmaceutical products must be based on knowledge on chronic ecotoxic effects of both active pharmaceutical ingredients as well as excipients. We believe that the impact pharmaceuticals have on the environment should be further studied and be given greater attention such that informed assessments of hazards as well as risks can be done.

Chemical process route selection based upon the potential toxic impact on the aquatic, terrestrial and atmospheric environments

Abstract This paper proposes a method to estimate the inherent environmental friendliness of a chemical process plant by considering the potential toxicity impact on the aquatic, terrestrial and atmospheric environments. A worst-case scenario of a total loss of containment in the plant is assumed. The method proposed by [Gunasekera, M.Y., Edwards, D.W. (2003). Estimating the environmental impact of catastrophic chemical releases to the atomosphere: an index method for ranking alternative chemical process routes. Trans. IChemE., Part B, Process Safety and Environmental Protection, 81(B6), 463–474] for determining the inherent atmospheric environmental friendliness of a chemical plant is combined with the method proposed by [Cave, S.R., Edwards, D.W. (1997). Chemical process route selection based on assessment of inherent environmental hazard. Computers Chem. Engng., 21, S965–S970], which estimates the inherent friendliness to the aquatic and terrestrial environments. Application of this method to six routes to produce methyl methacrylate shows that the acetone cyanohydrin based route is potentially the least inherently environmentally friendly. The highest potential hazard is observed in the aquatic environment due to the chemicals associated with the acetone cyanohydrin route.

Geostatistical Uncertainty Modelling for the Environmental Hazard Assessment During Single Erosive Rainstorm Events

This paper presents an environmental hazard assessment to account the impacts of single rainstorm variability on river-torrential landscape identified as potentially vulnerable mainly to erosional soil degradation processes. An algorithm for the characterisation of this impact, called Erosive Hazard Index (EHI), is developed with a less expensive methodology. In EHI modelling, we assume that the river-torrential system has adapted to the natural hydrological regime, and a sudden fluctuation in this regime, especially those exceeding thresholds for an acceptable range of flexibility, may have disastrous consequences for the mountain environment. The hazard analysis links key rainstorm energy variables expressed as a single-storm erosion index (EISTO), with impact thresholds identified using an intensity pattern model. Afterwards, the conditional probabilities of exceeding these thresholds are spatially assessed using non-parametric geostatistical techinques, known as indicator kriging. The approach was applied to a test site in river-torrential landscape of the Southern Italy (Benevento province) for 13 November 1997 rainstorm event.

Mode of action and aquatic exposure thresholds of no concern

Threshold concepts of toxicological concern are based on the possibility of establishing an exposure threshold value for chemicals below which no significant risk is to be expected. The objective of the present study is to address environmental thresholds of no toxicological concern for freshwater systems (ETNCaq) for organic chemicals. We analyzed environmental toxicological databases (acute and chronic endpoints) and substance hazard assessments. Lowest numbers and 95th-percentile values were derived using data stratification based on mode of action (MOA; 1 = inert chemicals; 2 = less inert chemicals; 3 = reactive chemicals; 4 = specifically acting chemicals). The ETNCaq values were derived by multiplying the lowest 95th percentile values with appropriate application factors; ETNCaq,MOA1-3 is approximately 0.1 microg/L. A preliminary analysis with complete MOA stratification of the databases shows that in the case of MOA1 or MOA2, the ETNCaq value could be even higher than 0.1 microg/L. A significantly lower ETNCaq,MOA4 value was observed based on the long-term toxicity information in the European Centre for the Ecotoxicology and Toxicology of Chemicals database. Application of the ETNCaq value in a tiered risk-assessment scheme may help chemical producers to set data-generation priorities and to refine or reduce animal use. It also may help to inform downstream users concerning the relative risk associated with their specific uses and be of value in putting environmental monitoring data into a risk-assessment perspective.

The Effect of Synthetic Surfactants on the Hydrobiological Mechanisms of Water Self-Purification

Long-term studies of the biological effect of surfactants, including the effect surfactants exert on filter feeders, are reviewed. The role of filter feeders in the functioning of freshwater and marine ecosystems is analyzed. New aspects in the assessment of environmental hazard due to the impact of chemical pollutants, including surfactants and detergents, are established.