Environmental Hazard Assessment Research Articles

Assessment of environmental and radiological health hazards due to heavy metals and radionuclides contents in utility water reservoirs' sediments

Heavy metals and natural radionuclides in sediments of Awara and Osse reservoirs, Ondo State, Nigeria have been measured using X-ray fluorescence and γ-ray spectrometry techniques. Heavy metals detected in the two reservoirs include K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Ba, Pb and Th. The average concentrations of the measured heavy and trace metals in the sediment of Awara dam vary as Fe>K>Ca>Mn>Ti> Sr>Cr>V>Rb>Zn>Ni>Cu while those of Osse dam vary as Ba>K>Fe>Ca> Mn>Sr>Ti>V>Rb>Cr>Zn>Ni>Th>Pb>Cu. Geoaccumulation index and enrichment factor evaluation of potentially toxic heavy metal contents in both reservoirs revealed that the two reservoirs are uncontaminated with hazardous heavy metals. Naturally occurring radionuclides (40K and 232Th) detected in the two reservoirs show values that are higher than their mean crustal value, while 226Ra is lower than the world mean crustal value. There is little or no ecological or radiological risk associated with the sediment of the two reservoirs.

Classification of baseline toxicants for QSAR predictions to replace fish acute toxicity studies.

Fish acute toxicity studies are required for environmental hazard and risk assessment of chemicals by national and international legislations such as REACH, the regulations of plant protection products and biocidal products, or the GHS (globally harmonised system) for classification and labelling of chemicals. Alternative methods like QSARs (quantitative structure-activity relationships) can replace many ecotoxicity tests. However, complete substitution of in vivo animal tests by in silico methods may not be realistic. For the so-called baseline toxicants, it is possible to predict the fish acute toxicity with sufficient accuracy from log Kow and, hence, valid QSARs can replace in vivo testing. In contrast, excess toxicants and chemicals not reliably classified as baseline toxicants require further in silico, in vitro or in vivo assessments. Thus, the critical task is to discriminate between baseline and excess toxicants. For fish acute toxicity, we derived a scheme based on structural alerts and physicochemical property thresholds to classify chemicals as either baseline toxicants (=predictable by QSARs) or as potential excess toxicants (=not predictable by baseline QSARs). The step-wise approach identifies baseline toxicants (true negatives) in a precautionary way to avoid false negative predictions. Therefore, a certain fraction of false positives can be tolerated, i.e. baseline toxicants without specific effects that may be tested instead of predicted. Application of the classification scheme to a new heterogeneous dataset for diverse fish species results in 40% baseline toxicants, 24% excess toxicants and 36% compounds not classified. Thus, we can conclude that replacing about half of the fish acute toxicity tests by QSAR predictions is realistic to be achieved in the short-term. The long-term goals are classification criteria also for further groups of toxicants and to replace as many in vivo fish acute toxicity tests as possible with valid QSAR predictions.

Environmental hazard assessment of slag waste of the heat-and-power plants

Environmental hazard assessment of slag waste of the heat-and-power plants

A framework for the environmental, health and safety hazard assessment for amine-based post combustion CO2 capture

Given the environmental concerns driving process developments and considering the size and scale of potential application of post combustion capture (PCC), it is important to fully understand process hazards. In this work we present an environmental, health and safety (EHS) hazard assessment framework for screening and comparing amine based PCC options. A multi-criteria assessment compares the performance of 7m Monoethanolamine (MEA), 4m Diethanolamine (DEA), 10m Diglycolamine (DGA), 8m Piperazine (PZ) and a blend of 7m Methyldiethanolamine (MDEA) with 2m PZ under a set of different process conditions. The EHS assessment takes into account varying circulating volumes, process conditions and potential for solvent degradation. The EHS assessment is also compared with operating costs and life cycle assessment (LCA) metrics. The EHS assessment is carried out on two levels. The first is less data intensive and provides a unified score that can be used to compare and screen process alternatives, while the second level studies the contribution of individual degradation products to different EHS hazard categories in detail. Results of the parametric study show that lean loading is an influential factor in determining first level EHS scores, process costs and environmental impacts and a trade-off is observed between EHS and LCA scores for some of the solvents. In the second level EHS assessment, the parent amine heavily influences most mass dependent hazard categories such as the fire/explosion, acute toxicity and air mediated effects category. Heat stable salts affect the solid waste category. Most degradation products are considered corrosive or irritant and therefore feature strongly in that category in addition to the parent amine. The second level EHS assessment is complemented with workplace exposure analysis to ensure the compliance with workplace threshold limits. Nitrosamines stand out for acute and chronic toxicity effects and are therefore used as an example to demonstrate the workplace exposure. Workplace amines and nitrosamine concentrations are estimated to assess long and potential short term worker exposure as a result of gas leakages and spills respectively. Indoor ventilation rates are inadequate to keep workplace amine and nitrosamine concentrations below the recommended guidelines. To reduce short term exposure effects, a steady state liquid nitrosamine concentration lower than 13.7mM is required. The results of the parametric study show that changing process conditions can lower nitrosamine concentrations, but can also shift the contribution of the parent amine and degradation products of the other hazard categories and affect LCA metrics. The sensitivity of the EHS and LCA results to model assumptions and conditions are tested by varying inlet NOx, expected aerosols and solvent degradation levels. Low NOx levels in the flue gas are required for PZ and MDEA-PZ systems to meet the nitrosamine concentration thresholds for environmental and health concerns. This study also highlights the need to consider hazard effects during early process design phases, identifies degradation related data gaps and critical process parameters towards more environmentally benign PCC design.

Magnetotelluric monitoring of coal seam gas depressurization

The depressurization of coal seam gas formations causes in situ fluids to migrate through pores and fractures in the earth. The removal or discharge of large volumes of water from coal measures reduces in situ fluid pressure allowing natural gas to be released from the coal matrix. This process results in a time-dependent resistivity variation in the subsurface. Increasing the connectivity of in situ fluids may lead to a reduction in resistivity of the targeted lithologies. A correct assessment of such resistivity variations is of significant interest not only for the industry to optimize production and extraction well locations but also for the regulatory bodies, in which a desire for a reliable method for monitoring changes in subsurface fluid distribution allows sound risk assessment of potential environmental hazards. From an industrial field study conducted in Queensland, Australia, we have found that the magnetotelluric (MT) method in the bandwidth of 100 Hz to 100 s could be used to monitor changes in the bulk resistivity of depressurized lithologies. Results from our study indicate the orientation of fluid flow resulting from depressurization, which can be mapped and directly attributed to spatial and temporal variations in permeability. The MT method is introduced as a low-cost, low-impact technology that can be used for short- and long-term environmental monitoring.

Assessing the relevance of ecotoxicological studies for regulatory decision making

Regulatory policies in many parts of the world recognize either the utility of or the mandate that all available studies be considered in environmental or ecological hazard and risk assessment (ERA) of chemicals, including studies from the peer-reviewed literature. Consequently, a vast array of different studies and data types need to be considered. The first steps in the evaluation process involve determining whether the study is relevant to the ERA and sufficiently reliable. Relevance evaluation is typically performed using existing guidance but involves application of "expert judgment" by risk assessors. In the present paper, we review published guidance for relevance evaluation and, on the basis of the practical experience within the group of authors, we identify additional aspects and further develop already proposed aspects that should be considered when conducting a relevance assessment for ecotoxicological studies. From a regulatory point of view, the overarching key aspect of relevance concerns the ability to directly or indirectly use the study in ERA with the purpose of addressing specific protection goals and ultimately regulatory decision making. Because ERA schemes are based on the appropriate linking of exposure and effect estimates, important features of ecotoxicological studies relate to exposure relevance and biological relevance. Exposure relevance addresses the representativeness of the test substance, environmental exposure media, and exposure regime. Biological relevance deals with the environmental significance of the test organism and the endpoints selected, the ecological realism of the test conditions simulated in the study, as well as a mechanistic link of treatment-related effects for endpoints to the protection goal identified in the ERA. In addition, uncertainties associated with relevance should be considered in the assessment. A systematic and transparent assessment of relevance is needed for regulatory decision making. The relevance aspects also need to be considered by scientists when designing, performing, and reporting ecotoxicological studies to facilitate their use in ERA. Integr Environ Assess Manag 2017;13:652-663. © 2016 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Environmental hazard assessment of contaminated soils in Antarctica: Using a structured tier 1 approach to inform decision-making

Generally, Antarctica is considered to be an untouched area of the planet; however, the region's ecosystems have been subject to increased human pressure for at least the past half-century. This study assessed soils of Fildes Peninsula, where trace element pollution is thought to prevail. Four soil samples were collected from different locations and assessed following tier 1 methodologies for chemical and ecotoxicological lines of evidence (LoE) used in typical soil Environmental Risk Assessment (ERA). Trace element quantification was run on soil samples and sequential extracts, and elutriates were used to address their ecotoxicity using a standard ecotoxicological battery. The highest levels of trace elements were found for Cr, Cu, Ni and Zn, which were well above baseline levels in two sites located near previously identified contamination sources. Trace element concentrations in soils were compared with soil quality guidelines to estimate the contribution of the chemical LoE for integrated risk calculations; risk was found high, above 0.5 for all samples. Total concentrations in soil were consistent with corresponding sequentially extracted percentages, with Cu and Zn being the most bioavailable elements. Bacteria did not respond consistently to the elutriate samples and cladocerans did not respond at all. In contrast, the growth of microalgae and macrophytes was significantly impaired by elutriates of all soil samples, consistently to estimated trace element concentrations in the elutriate matrix. These results translated into lower risk values for the ecotoxicological compared to the chemical LoE. Nevertheless, integrated risk calculations generated either an immediate recommendation for further analysis to better understand the hazardous potential of the tested soils or showed that the soils could not adequately sustain natural ecosystem functions. This study suggests that the soil ecosystem in Fildes has been inadequately protected and supports previous claims on the need to reinforce protection measures and remediation activities.

Separation of Bacteria, Protozoa and Carbon Nanotubes by Density Gradient Centrifugation.

Sustainable production and use of carbon nanotube (CNT)-enabled materials require efficient assessment of CNT environmental hazards, including the potential for CNT bioaccumulation and biomagnification in environmental receptors. Microbes, as abundant organisms responsible for nutrient cycling in soil and water, are important ecological receptors for studying the effects of CNTs. Quantification of CNT association with microbial cells requires efficient separation of CNT-associated cells from individually dispersed CNTs and CNT agglomerates. Here, we designed, optimized, and demonstrated procedures for separating bacteria (Pseudomonas aeruginosa) from unbound multiwall carbon nanotubes (MWCNTs) and MWCNT agglomerates using sucrose density gradient centrifugation. We demonstrate separation of protozoa (Tetrahymena thermophila) from MWCNTs, bacterial agglomerates, and protozoan fecal pellets by centrifugation in an iodixanol solution. The presence of MWCNTs in the density gradients after centrifugation was determined by quantification of 14C-labeled MWCNTs; the recovery of microbes from the density gradient media was confirmed by optical microscopy. Protozoan intracellular contents of MWCNTs and of bacteria were also unaffected by the designed separation process. The optimized methods contribute to improved efficiency and accuracy in quantifying MWCNT association with bacteria and MWCNT accumulation in protozoan cells, thus supporting improved assessment of CNT bioaccumulation.

Innovation and model organisms for the environmental hazard assessment of engineered nanomaterials

Innovation and model organisms for the environmental hazard assessment of engineered nanomaterials

Assessing Cancer Risk from Heavy Metals in Recycling Waste Electrical and Electronic Equipment: Preliminary Results from the WEENMODELS European Life Programme

Introduction The growing amount of waste derived from electrical and electronic equipment (WEEE) poses significant challenges to waste management, due to the presence of toxic chemicals with environmental and health implications for the general population and for occupationally-exposed workers. Methods Based on an toxicological and epidemiologic evaluation, we carried out a health risk assessment to evaluate the cancer risk deriving from environmental and occupational exposure to heavy metals released during different WEEE recycling procedures (electronic scrap in blister copper, treatment of metals recovery in copper smelter, treatment of shredding, pyrometallurgical treatment of Li-ion battery). We considered the typical WEEE production in a municipality of 150.0000 inhabitants, carrying out a Life Cycle Assessment. Outdoor (1 square km around a treatment plant) and indoor (for a factory volume of 3200 m3) emissions generated during the WEEE recycling procedures were computed. In particular, we estimated the amount of Cd, Ni and As inhaled by the potentially exposed population. We computed the cancer risk due to inhalation of these heavy metals in residents and workers using the methodology proposed by the California Office of Environmental Health and Hazard Assessment Results For the metals considered, our results showed negligible cancer risk (from 2,21x10-11 to 4,31x10-08) for the general population around the plant. On the converse, occupational exposures linked to specific procedures were associated with a cancer risk of 1,42x10-3 for workers in the shredding procedures mainly due to Ni exposure, and of 4,68x10-4 for workers with electronic scrap and exposed to As. Conclusions Based on our preliminary results from an integrated toxicological and epidemiologic approach, WEEE life cycle may be linked to health risks for workers in the recycling procedures, while it does not seem to adversely affect health of the general population around the treatment plants.

Occurrence and distribution of perfluoroalkyl acids (PFAAs) in surface water and sediment of a tropical coastal area (Bay of Bengal coast, Bangladesh)

This study reports the first evidence of perfluoroalkyl acids (PFAAs) in surface waters and sediments collected from the coastal area of Bangladesh. Fifteen target PFAAs, including C4–14-PFCAs (perfluoroalkyl carboxylates) and C4, C6, C8, and C10-PFSAs (perfluoroalkyl sulfonates), were quantified by HPLC–MS/MS. The ΣPFAAs in surface water and sediment samples were in the range of 10.6 to 46.8ng/L and 1.07 to 8.15ng/gdw, respectively. PFOA in water (3.17–27.8ng/L) and PFOS in sediment samples (0.60–1.14ng/gdw) were found to be the most abundant PFAAs, and these concentrations were comparable to or less than most other reported values, particularly those recorded from the coastal areas of China, Japan, Korea and Spain. The majority of the monitored PFAAs did not show clear seasonal variation. The southeastern part (Cox’s Bazar and Chittagong) of the Bangladeshi coastal area was more contaminated with PFAAs than the southern (Meghna Estuary) and southwestern parts (Sundarbans). Industrial and municipal wastewater effluents, ship breaking and port activities were identified as potential sources of the PFAA contamination in this region. Field-based sediment water distribution coefficients (KD) were calculated and corrected for organic carbon content (KOC), which reduced the variability between samples. The values of log KD (1.63–2.88) and log KOC (4.02–5.16) were higher than previously reported values, which may indicate that the partitioning of PFAAs in a tropical coastal ecosystem is different from other ecosystems, such as temperate and sub-tropical regions. Although a preliminary environmental hazard assessment indicated that PFOA or PFOS levels do not currently exceed the acute safety thresholds, we should keep in mind that they are bioavailable and can accumulate in the food chain. Therefore, the ubiquity of PFAAs in the coastal area of Bangladesh warrants further studies characterizing their specific sources and the potential long-term risks they present to both humans and wildlife.

Development of algal interspecies correlation estimation models for chemical hazard assessment.

Web-based Interspecies Correlation Estimation (ICE) is an application developed to predict the acute toxicity of a chemical from 1 species to another taxon. Web-ICE models use the acute toxicity value for a surrogate species to predict effect values for other species, thus potentially filling in data gaps for a variety of environmental assessment purposes. Web-ICE has historically been dominated by aquatic and terrestrial animal prediction models. Web-ICE models for algal species were essentially absent and are addressed in the present study. A compilation of public and private sector-held algal toxicity data were compiled and reviewed for quality based on relevant aspects of individual studies. Interspecies correlations were constructed from the most commonly tested algal genera for a broad spectrum of chemicals. The ICE regressions were developed based on acute 72-h and 96-h endpoint values involving 1647 unique studies on 476 unique chemicals encompassing 40 genera and 70 species of green, blue-green, and diatom algae. Acceptance criteria for algal ICE models were established prior to evaluation of individual models and included a minimum sample size of 3, a statistically significant regression slope, and a slope estimation parameter ≥0.65. A total of 186 ICE models were possible at the genus level, with 21 meeting quality criteria; and 264 ICE models were developed at the species level, with 32 meeting quality criteria. Algal ICE models will have broad utility in screening environmental hazard assessments, data gap filling in certain regulatory scenarios, and as supplemental information to derive species sensitivity distributions. Environ Toxicol Chem 2016;35:2368-2378. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

Comparative ecotoxicology study of two neoteric solvents: Imidazolium ionic liquid vs. glycerol derivative

In this study we have compared the acute ecotoxicity of two solvents, with very different structure and origin, but sharing many physical-chemical properties, so they can be used for similar purposes; a well-known ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) and a solvent partially derived from biomass, 3-bis(2,2,2-trifluoroethoxy)propan-2-ol (BTFIP). We have used three biomodels (Vibrio fischeri, Daphnia magna and Danio rerio) and performed the comparison applying the Environmental, Health and Safety (EHS) hazard assessment. According to the results, ecotoxicity of [BMIM][PF6] and BTFIP is quite similar in the simplest model Vibrio fischeri, while in Daphnia magna [BMIM][PF6] is clearly more toxic. However, in Danio rerio, toxicity of these chemicals is again quite similar and both can be classified as “nontoxic”. The higher index value of [BMIM][PF6] in water mediate effect in the EHS assessment indicates that this ionic liquid is more dangerous than BTFIP, although accumulation and degradation properties have not been taken into account. Further studies will be necessary to ascertain these conclusions.

Potential for Reuse of E-Plastics through Processing by Compression Molding

The amounts of e-waste, consisting of metal (e-metals) and plastic (e-plastics) streams from electronic goods, are increasing in the United States and elsewhere. The e-metals waste streams are being recycled to a reasonable degree due to the value of precious metals. E-plastic waste streams currently are not recycled or reused to a significant extent. As a result, most e-plastics are disposed of by landfilling or thermal treatment, or sent overseas for alleged recycling or reuse, any of which could result in unsafe worker exposure and release into the environment. Two of the major barriers to e-plastics’ reuse or recycling are the mixed plastic content and the presence in the e-plastics of flame retardants (FR), of which two classes in particular, the brominated flame retardants (BFR) and organo-phosphorus flame retardants (OPFR), have associated health concerns. The major goal of this project is to investigate the possibility of direct reuse of e-plastics in compression molding. Preliminary data generated have identified a molding procedure that yields remanufactured e-plastics having a tensile strength of 29.3 MPa. This moderate strength level is suspected to be due to inclusions of plastic bits that did not melt and internal voids from out-gassing. Handheld X-ray fluorescence (XRF) was utilized to characterize elemental components in the e-plastics tested for compression molding. Several high “hits” for Br were found that could not be predicted visually. The preliminary XRF data for BFR and OPFR in this work are helpful for environmental and occupational hazard assessments of compression molding activities. Additionally, methods are suggested to characterize the metals, BFR, and OPFR content of the e-plastics using several different additional laboratory analytical techniques to determine the suitability for cost-effective and easy-to-use technologies.

Evaluation of the integrated testing strategy for PNEC derivation under REACH

Species sensitivity evaluation represents an approach to avoid chronic toxicity testing of aquatic vertebrates in accordance with the animal welfare concept of the EU chemicals regulation. In this study a data set of chemicals is analysed for relative species sensitivity between Daphnia and fish in chronic testing to evaluate under what condition chronic fish tests can be waived without underestimating the environmental hazard. Chronic fish toxicity is covered in 84% of the evaluated substances by the chronic invertebrate test and an assessment factor of 50. Thus, animal testing can be avoided in environmental hazard assessment for many chemicals. Moreover, it is shown that species sensitivity in chronic testing is associated with species sensitivity in acute testing. The more sensitive species in chronic testing is predicted with a high probability if a species is >5x more sensitive in acute testing. If substances are comparable or more toxic to Daphnia in acute testing than to fish chronic fish toxicity is covered by the chronic Daphnia test and an assessment factor of 50 in about 95% of the evaluated cases. To provide decision support for the regulation of chemicals a categorization scheme on relative sensitivity comparison is presented.

Criteria for Reporting and Evaluating ecotoxicity Data (CRED): comparison and perception of the Klimisch and CRED methods for evaluating reliability and relevance of ecotoxicity studies.

BackgroundThe regulatory evaluation of ecotoxicity studies for environmental risk and/or hazard assessment of chemicals is often performed using the method established by Klimisch and colleagues in 1997. The method was, at that time, an important step toward improved evaluation of study reliability, but lately it has been criticized for lack of detail and guidance, and for not ensuring sufficient consistency among risk assessors.Results A new evaluation method was thus developed: Criteria for Reporting and Evaluating ecotoxicity Data (CRED). The CRED evaluation method aims at strengthening consistency and transparency of hazard and risk assessment of chemicals by providing criteria and guidance for reliability and relevance evaluation of aquatic ecotoxicity studies. A two-phased ring test was conducted to compare and characterize the differences between the CRED and Klimisch evaluation methods. A total of 75 risk assessors from 12 countries participated. Results show that the CRED evaluation method provides a more detailed and transparent evaluation of reliability and relevance than the Klimisch method. Ring test participants perceived it to be less dependent on expert judgement, more accurate and consistent, and practical regarding the use of criteria and time needed for performing an evaluation.ConclusionsWe conclude that the CRED evaluation method is a suitable replacement for the Klimisch method, and that its use may contribute to an improved harmonization of hazard and risk assessments of chemicals across different regulatory frameworks.Electronic supplementary materialThe online version of this article (doi:10.1186/s12302-016-0073-x) contains supplementary material, which is available to authorized users.

A weight-of-evidence approach to assess chemicals: case study on the assessment of persistence of 4,6-substituted phenolic benzotriazoles in the environment.

BackgroundOne important purpose of the European REACH Regulation (EC No. 1907/2006) is to promote the use of alternative methods for assessment of hazards of substances in order to avoid animal testing. Experience with environmental hazard assessment under REACH shows that efficient alternative methods are needed in order to assess chemicals when standard test data are missing. One such assessment method is the weight-of-evidence (WoE) approach. In this study, the WoE approach was used to assess the persistence of certain phenolic benzotriazoles, a group of substances including also such of very high concern (SVHC).ResultsFor phenolic benzotriazoles, assessment of the environmental persistence is challenging as standard information, i.e. simulation tests on biodegradation are not available. Thus, the WoE approach was used: overall information resulting from many sources was considered, and individual uncertainties of each source analysed separately. In a second step, all information was aggregated giving an overall picture of persistence to assess the degradability of the phenolic benzotriazoles under consideration although the reliability of individual sources was incomplete.ConclusionsOverall, the evidence suggesting that phenolic benzotriazoles are very persistent in the environment is unambiguous. This was demonstrated by a WoE approach considering the prerequisites of REACH by combining several limited information sources. The combination enabled a clear overall assessment which can be reliably used for SVHC identification. Finally, it is recommended to include WoE approaches as an important tool in future environmental risk assessments.

How credible are the study results? Evaluating and applying internal validity tools to literature-based assessments of environmental health hazards

Environmental health hazard assessments are routinely relied upon for public health decision-making. The evidence base used in these assessments is typically developed from a collection of diverse sources of information of varying quality. It is critical that literature-based evaluations consider the credibility of individual studies used to reach conclusions through consistent, transparent and accepted methods. Systematic review procedures address study credibility by assessing internal validity or “risk of bias” — the assessment of whether the design and conduct of a study compromised the credibility of the link between exposure/intervention and outcome. This paper describes the commonalities and differences in risk-of-bias methods developed or used by five groups that conduct or provide methodological input for performing environmental health hazard assessments: the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group, the Navigation Guide, the National Toxicology Program's (NTP) Office of Health Assessment and Translation (OHAT) and Office of the Report on Carcinogens (ORoC), and the Integrated Risk Information System of the U.S. Environmental Protection Agency (EPA-IRIS). Each of these groups have been developing and applying rigorous assessment methods for integrating across a heterogeneous collection of human and animal studies to inform conclusions on potential environmental health hazards. There is substantial consistency across the groups in the consideration of risk-of-bias issues or “domains” for assessing observational human studies. There is a similar overlap in terms of domains addressed for animal studies; however, the groups differ in the relative emphasis placed on different aspects of risk of bias. Future directions for the continued harmonization and improvement of these methods are also discussed.

Integrated Assessment of Environmental Hazard of Enterprises and Territories

There was presented methodology of integrated assessment of environmental hazard, whose main elements are: identification of sources of environmental hazard; assessment of the degree of danger of existing environmental situation; analysis of environmental risks and the assessment of the potential environmental hazard; integrated assessment of existing and potential environmental hazard in a particular area. There was presented systematization of sources of environmental hazard and methods of identifying the existing and potential sources of environmental hazard. Hazard degree assessments of existing environmental situation include landscape identification of the territory, the definition of the total anthropogenic load, and integrated assessment of environment pollution. Environmental hazards in a particular area is determined by the combined action of existing and potential sources of environmental hazards, as well as a degree of danger of existing environmental situation. The presented method was tested in the evaluation of environmental hazards in the Stavropol Kray territory. The proposed method allows carrying out a qualitative assessment of environmental hazard of enterprises and territories, the results of which form the basis for developing measures to ensure environmental safety.

Computational assessment of environmental hazards of nitroaromatic compounds: influence of the type and position of aromatic ring substituents on toxicity

Computational assessment of environmental hazards of nitroaromatic compounds: influence of the type and position of aromatic ring substituents on toxicity