Soil assessment after chemical accidents using metabolic profiling and microbial community evaluation

This study investigated the effects of accidental contamination of soils with phenol, toluene, nitric acid, and hydrogen fluoride (HF) by simulating chemical leakage in the soil with/without rain and characterizing the resulting metabolites and microbial. In the case of acid leakage, pH and cation exchange capacity were decreased, and the content of fluoride ion was increased in case of HF leakage. Using mass spectrometry-based metabolomics analysis, phytosphingosine was detected as a distinguishing metabolite in soils contaminated with phenol and HF in rain conditions. Microbial communities were identified by 16s rRNA metagenome sequencing. Sphingomonas was one of the dominant species in soils contaminated with phenol and HF. These results suggest that phytosphingosine and Sphingomonas might be used as biomarkers to evaluate the status of soils contaminated with phenol or HF. Under simulated rain conditions, the species alpha-diversity index of soil microbes and the physicochemical properties of the soil indicated values close to those of the uncontaminated soil. Rain played an important role in the recovery of microbial and metabolic profiles after chemical accidents. Metabolic profiling and microbial community analysis can serve as a diagnostic tool for ecotoxicological research at chemical accident sites.

A multidisciplinary assessment of the impact of spilled acids on geoecosystems: an overview

We developed and applied a multidisciplinary approach to the impact of an accidentally spilled acid on the underlying geomedia and subsurface environment, based on the concept of geoecosystem. We used mineralogical, geochemical, microbiological, and ecotoxicological techniques to identify and assess the multiple aspects involved. First, we constructed a conceptual model for the acid interactions with the underlying subsurface environment by introducing the concept of a geoecosystem-a multicomponent system composed of inorganic, organic, and biological components to describe the subsurface environment. Second, we designed and manufactured a two dimensional cell to visualize acid transport through geomedia. Third, we hypothesized that the acids are neutralized through dissolution of minerals and protonation of functional groups on the surfaces of minerals and organic matter. We tested this hypothesis by conducting batch-type geomedia-acid reaction and surface titration experiments. Fourth, we observed changes in soil microbial communities before and after the acid exposure and neutralization treatment. Fifth, we performed flow-through experiments using columns packed with soil samples pre-contaminated with arsenic to investigate potential longer term, secondary effects of remnant acids on geoecosystems. Finally, we conducted ecotoxicological investigations using various geomedia and observed that suitability of the geoecosystem as a habitat deteriorated to different degrees depending on the respective systems' acid neutralizing power. We conclude that a holistic understanding of the interactions among the multiple components of geoecosystems and subsequent estimation of the influenced area requires a multidisciplinary approach such as those used in this study. Based on the findings of this study, we propose geoecosystems' vulnerability defined as the reciprocal of their acid-neutralizing capacity against the moving acid fronts and present this concept as central to a quantitative assessment of the impact of acid spills on geoecosystems. We also inventoried the essential components, factors, and parameters necessary in developing geoecosystems' acid vulnerability assessment system.

A Putative Adverse Outcome Pathway Relevant to Carcinogenicity Induced by Sulfuric Acid in Strong Inorganic Acid Mists

Based on epidemiological studies, an International Agency for Research on Cancer Working Group determined that strong inorganic acid mists containing sulfuric acid are carcinogenic to human even though, sulfuric acid, per se, is not. Accumulative studies indicate that there is a link between chronic occupational exposure to sulfuric acid mists and an increased risk of laryngeal cancer. Unintended, acute exposure to sulfuric acid mists can cause corrosive damage to target tissues depending on the route of exposure. This review compares the toxicity and carcinogenicity of sulfuric acid mists compared to other strong inorganic acid mists. It also examines the routes and duration of exposure (short-term, prolonged, and long-term). In vivo evidence does not support or refute the carcinogenicity of sulfuric inorganic mists even though its co-carcinogenic or promoting potential has been considered. On the basis of existing evidence on sulfuric acid mist toxicity, we suggested a putative adverse outcome pathway (AOP) relevant to carcinogenicity caused by mists containing sulfuric acid. A possible key factor involved in sulfuric acid mist carcinogenesis is the genotoxic effects of low pH since it can increase instability in chromosomes and DNA. A putative AOP for sulfuric acid mist carcinogenicity would help generate better risk assessments and more accurate predictions regarding the risk of developing cancer due to prolonged exposure. Establishing an AOP would also be useful for future studies examining the carcinogenicity of other strong inorganic mists.

Assessing human vulnerability in industrial chemical accidents: a qualitative and quantitative methodological approach

Iran as a developing country is experiencing the industrialization process quickly and is thus exposed to different industrial hazards mostly derived from chemicals. In the light of this problem, this study estimated the human vulnerability in chemical accidents using the software simulation of accidental chlorine gas releases. A mixed method (qualitative and quantitative) study carried out in 4 phases during 2015-2017 in Ray County, Tehran Province. It included a systematic literature review, software simulation, Fuzzy Delphi Analytical Hierarchy Process (FDAHP) hierarchy process study, and creating a reliable tool for purpose of this study in at-risk areas. The valuable finding indicated that decreasing the human vulnerability depends on both social and physical characteristics of area and even the social vulnerability indicators have more important role when compared with the physical vulnerability indicators. The statistical analysis revealed that the human vulnerability has the significant relationship with factors such as type of living place (rural or urban) areas, nationality, economic situation of households, the distance between housing and the nearest exit to main road, health centers, and manufacturing or storing chemical plants (P value < 0.01). The result also showed that the area under study is vulnerable from average to very high, both in its physical and social domains, against industrial chemical accidents. Additional comparative studies are needed to develop and generalize the appropriate set of indicators of human vulnerability to human induced disasters in Iran.

Proximity to extremely hazardous substances for people with disabilities: A case study in Houston, Texas

BACKGROUND

While numerous studies have found socially disadvantaged groups such as minorities and low-income individuals to be disproportionately distributed with respect to various health hazards and pollution sources, previous research has not examined if people with disabilities reside near facilities where accidental releases of extremely hazardous substances are likely to occur.

OBJECTIVE

Using data from the 2011-2015 American Community Survey estimates and facilities submitting Risk Management Plans (RMPs) to the Environmental Protection Agency (EPA), the distribution of proximity to RMP facilities is compared to the disability characteristics of the civilian noninstitutionalized population in Harris County, Texas. The goal is to determine whether neighborhoods containing a higher proportion of disabled individuals are located near RMP facilities, after controlling for relevant socio-demographic factors.

METHODS

Proximity to RMP facilities is calculated at the census tract level using a spatial enumeration methodology developed by the EPA. Statistical analyses are based on descriptive comparisons, bivariate correlations, and multivariate generalized estimating equations--a modeling technique appropriate for clustered data.

RESULTS

RMP facility proximity increases significantly as the percentage of overall disability, as well as the percentages for specific types of disability increase, after accounting for population density, racial/ethnic composition, and socioeconomic status of neighborhoods. Disabled individuals with hearing and cognitive difficulties are particularly more likely to reside near RMP facilities.

CONCLUSIONS

These findings emphasize the growing need to consider individuals with physical and mental disabilities in future research on environmental justice and health risk disparities, as well as evacuation planning for chemical accidents.

Survey of awareness about hazardous chemicals of residents living near chemical plants in South Korea

With economic growth, the use of chemicals has continually increased, resulting in an increase of chemical accidents. Chemical accidents pose a life threat and can lead to many health problems among the residents living in close proximity to chemical plants. This study aimed to investigate the awareness of the residents living near chemical plants about hazardous chemicals, as well as to survey the awareness of workers who do not directly handle chemicals at chemical plants (WNHCs). To this end, a questionnaire survey was conducted among a total of 600 residents and 160 WNHCs. The questionnaire was composed of three items: awareness of chemical risk, awareness of countermeasures in chemical accidents, and imperious necessity of PPE (personal protective equipment). Statistical analysis of the data was performed with the Statistical Package for Social Sciences (SPSS) version 18.0. The results show that the government needs to complement the notification system of chemical risk for residents who live close to chemical plants. The highest priority of PPE which residents want to prepare for chemical accidents was respiratory protective equipment (RPE). They responded that, if necessary to purchase PPE, they could bear a portion of the expenses (up to US $30). This study provides basic data for the development of programs and policies on chemical safety relevant for the residents living in close proximity to chemical plants in South Korea.