US Environmental Protection Agency Research Articles

Diverting Food Waste From Landfill in Exemplar Hospital Foodservices: A Qualitative Study

BackgroundThe US Environmental Protection Agency Food Recovery Hierarchy suggests methods for diverting food waste from landfill. Knowledge of how hospital foodservices implement food waste management strategies could help modernize food waste practices. ObjectiveThe aim of this study was to explore hospital staff members’ experiences of implementing a food waste management strategy to divert food waste from landfill in their hospital foodservice, including the journey, challenges, and facilitators of this practice change. DesignA qualitative study was conducted in 2022-2023 using semi-structured interviews. Participants/settingEighteen participants were staff members with knowledge of the food waste management strategy from 14 exemplar hospitals in United States, Spain, Scotland, and Australia using strategies to divert food waste from landfill within the last 10 years. Analyses performedMapping and thematic analysis were undertaken to code and identify themes from the interviews that described staff members’ experiences of the journey to implement the strategy. ResultsSix hospitals donated food, 1 transferred food waste for animal feed, 4 used an industrial solution, and 3 sent food waste for composting. A common journey pathway for successful implementation was identified from participants' experiences. It features the following 6 phases: idea, preparation, roll out, maintenance, established practice, and evolution. Facilitators included legislation, enthusiastic staff members, executive support, and “luck.” Challenges were smells, occasions when food waste was not collected, equipment breakage, and funding depletion. ConclusionsThis study identified a common journey pathway for implementing a food waste management strategy in hospital foodservices that can be used to anticipate and prepare for the steps in the implementation process.

Smartphone-integrated colorimetric and microfluidic paper-based analytical devices for the trace-level detection of permethrin.

Permethrin is a pyrethroid pesticide and insect repellent that prevents mosquito-borne infections like dengue and malaria in tropical areas. This work describes a new colorimetric sensor based on metronidazole-stabilized silver nanoparticles (MTZ-AgNPs) for the first rapid, sensitive, and selective permethrin detection. The MTZ-AgNPs-based colorimetric sensor has a limit of detection (LOD) of 0.0104µM and a limit of quantification (LOQ) of 0.0348µM, respectively. The sensor is further integrated with smartphone and microfluidic fabrication of paper-based analytical devices (µPADs) for real-time and on-site detection of permethrin. Under optimal settings, no potential environmental contaminants interfere with permethrin detection, confirming its high selectivity. Finally, the practical applicability of sensors is confirmed in real tomato and apple extract samples. The US environmental protection agency's recommended UPLC method validated the detection efficiency of the proposed colorimetric sensor. The % recoveries from UPLC and MTZ-AgNPs suggest that the present sensor can quantitatively analyze permethrin in real samples.

Визначення відповідності вітчизняної бази гігієнічних нормативів канцерогенних речовин в атмосферному повітрі населених місць вимогам ЄС

The purpose of this work was to assess the safety of domestic (hygienic) standards for carcinogenic substances in the atmospheric air of populated areas and determine the concentration level corresponding to the acceptable risk indicator. Materials and methods. Bibliosemantic, bibliographic and hygienic research methods were used in this research. The results were obtained based on the collection and analysis of data on chemical carcinogenic compounds dangerous to humans, based on materials from international Directives, domestic regulatory frameworks and the IARC database. To assess the danger of individual substances and hygienic regulatory levels, risk indicators were determined according to recommended methodological documents. Indicators of reference concentrations for carcinogenic substances standardized in Ukraine were taken from data of the integrated risk information system (IRIS) US EPA. Results and discussion: the studies conducted indicate the need to revise the hygienic standards for carcinogenic substances included in the domestic regulatory framework for the atmospheric air of populated areas. The current standards for the most part exceed the level of acceptable or acceptable risk of probable cancer development among the population and those employed in production. This issue can be resolved by using an accelerated methodology, which is based on the calculation of the dose-risk scale. Accepted hygienic standards for the indicator of carcinogenic risk should be considered as annual averages for the atmospheric air of populated areas, and the current average daily concentrations according to international recommendations should be aimed at preventing acute exposure to chemical carcinogens within 24 hours and manifest themselves over a period of about 14 days. Conclusion: sanitary (hygienic) standards for carcinogenic substances in the air, included in the domestic bases, overwhelmingly exceed the level of permissible (acceptable) risk of cancer development and do not ensure safety for the population and persons involved in production and require revision in accordance with the requirements of the EU countries and the USA. It is proposed to resolve this issue using an accelerated methodology, which is based on the calculation of the dose-risk relationship (scale).

Pyramid-shaped solar evaporator with high-efficient interfacial evaporation and salt harvesting capability

Solar-driven interfacial evaporation shows significant potential for addressing challenges associated with freshwater shortages and environmental pollution. In this study, a series of pyramid-shaped solar evaporators were fabricated to achieve highly efficient solar interfacial evaporation. The optimized triangular pyramid evaporator exhibits exceptional adaptability and stability in seawater desalination and wastewater purification, thanks to its excellent light capture and photothermal conversion capacity, controlled water supply, effective thermal management, and energy input from the environment. It maintains a high evaporation rate and energy efficiency even in highly concentrated saltwater and strongly acidic or alkaline solutions. The 3D conical evaporation structure promotes top-preferential crystallization, directing the crystallization process towards the apex and facilitating efficient spatial salt harvesting. The collected condensate meets the drinking water requirements set by the World Health Organization (WHO) and the US Environmental Protection Agency (EPA). Under outdoor evaporation conditions, the evaporator achieves a daily freshwater production of 24.93 and a salt production of 2.09 kg m−2 d−1, fully satisfying the needs of a typical three-person household. Our microstructure control strategy for enhancing solar interfacial evaporation offers valuable insights and inspiration to researchers aiming to improve the performance of 3D solar evaporators.

Beyond Haze: Unveiling the Health Crisis of Urban Smog

With the industrial growth and urbanization in large cities of Pakistan, the smog has become a lurking adversary amidst the haze impacting millions of people every winter season. Pakistan ranks at number 3 in the countries with poor air quality as of 2019, the main reason of which is the persistent smog.  It is formed the presence of severe atmospheric pollutants suspended in air which gives it a yellowish black dense appearance. These pollutants mainly originate from industries due to the burning of fuels in industries, and from automobile exhausts due to the release of harmful gases such as ozone, nitrogen oxides and sulfur oxide along with the particulate matter such as dust and volatile compounds in air. It not only reduces visibility and obscures the skyline but is known to have serious implications for human health. Various studies associate smog with the respiratory and eye infections, allergies, and lungs cancer. The particulate matter present in the smog such as PM10 reach the lower levels of the respiratory tract and is responsible for irritation and allergies. Moreover, they carry other harmful materials, such hydrocarbons and poisonous gases with them as well that enter the blood stream via gaseous in alveoli [1]. The constituents in smog have been reported to elevate the risk of adenocarcinoma and squamous cell carcinoma in lungs in the people with chronic respiratory conditions. People from all age groups are affected with the youngest and immunocompromised individuals more susceptible to perilous effects of smog depending upon the time of exposure. Apart from respiratory system, there are various reports which link smog with the cardiovascular system issues as well. Researchers from the US Environmental Protection Agency (EPA) have proved the long-term exposure to PM2.5 can result in myocardial infarction and decreased life expectancy [2]. A number of multifaceted strategies are required to address this health crisis. Regulatory policies for the controlled emission of harmful matter in the air, and plans for the introducing cleaner technologies may prove beneficial to mitigate this risk and improve the overall air quality. Public awareness is equally critical to equip general masses with the knowledge about the adverse effects of smog and ways to prevent them. Smog is not merely an environmental concern, it’s a public health emergency which demands urgent attention. It’s a collected responsibility of policy makers and communities to revitalize the urban environments steering towards healthier tomorrows.

Monitoring and Risk Assessment of Polycyclic Aromatic Hydrocarbons in Mainstream Cigarette Smoke

Objectives : Cigarette smoking is an important factor in human exposure to polycyclic aromatic hydrocarbons (PAHs). Machine-smoking methods have been devised to evaluate inhalation exposure to mainstream cigarette smoke. However, there have been only a few studies that have employed these methods for PAH monitoring in Korea.Methods : Total particulate matter samples were collected from the mainstream smoke of five different cigarette types using the ISO 3308 standard smoking method. The samples were analyzed for 16 PAHs using a gas chromatograph/mass spectrometer (GC/MS) following extraction and clean-up procedures.Results and Discussion : The 16 PAH levels of cigarette samples ranged from 87.1 ng/cig to 247.4 ng/cig with an average of 135.4 ng/cig. The average fractions of PAHs classified by the number of rings were as follows: 15% (2 rings), 37% (3 rings), 43% (4 rings), 4% (5 rings), and 1% (6 rings). Diagnostic ratios suggested that the characteristics of PAH pollution in mainstream cigarette smoke were similar to those of biomass burning but different from those of ambient air. The carcinogenic risks of PAHs exceeded the risk threshold of the US EPA (1.0E-06) for the 10%, 30%, and 20% exposure groups of adult males, adult females, and all adults, respectively.Conclusion : This study highlights the significance of mainstream cigarette smoke in examining human inhalation exposure to PAHs and carcinogenic risks, which are primarily influenced by cigarette smoking rather than ambient air. These findings can contribute to a comprehensive assessment of inhalation exposure to PAHs and provide guidance for the development of environmental health policies aimed at reducing such exposure.

High geogenic soil thallium shows limited impact on bacterial community

Thallium (Tl) is a highly toxic trace metal, included in the US EPA list of priority pollutants. Even though its toxicity is potentially higher or comparable to Cd or Hg, its environmental impact is largely unknown. Despite its toxicity, only a few recent studies are mapping the impact of recently introduced Tl on soil microbial communities, namely in agricultural systems but no studies focus on its long term effect. To complement the understanding of the impact of Tl on soil, this study aims to describe the influence of extremely high naturally occurring Tl concentration (50 mg/kg of potentially bioavailable Tl) on soil microbial communities. Our investigation concentrated on samples collected at Buus (Erzmatt, Swiss Jura, Switzerland), encompassing forest and meadow soil profiles of the local soil formed on hydrothermally mineralized dolomite rock, which is naturally rich in Tl. The soil profiles showed a significant proportion of potentially bioavailable Tl. Yet, even this high concentration of Tl has a limited impact on the richness of the soil bacterial community. Only the meadow soil samples show a reduced richness compared to control samples. Furthermore, our analysis of geogenic Tl contamination in the region unveiled a surprising finding: compared to other soils of Switzerland and in stark contrast to soils affected by recent mining activities, the structure of the bacterial community in Buus remained relatively unaffected. This observation highlights the unique ability of soil microbial communities to withstand extreme Tl contamination. Our study advances the understanding of Tl's environmental impact and underscores the resilience of soil microbes in the face of severe long-term contamination.

Spatiotemporally resolved emissions and concentrations of styrene, benzene, toluene, ethylbenzene, and xylenes (SBTEX) in the US Gulf region

Abstract. Styrene, benzene, toluene, ethylbenzene, and xylenes (SBTEX) are established neurotoxicants. SBTEX contains hazardous air pollutants (HAPs) that are released from the petrochemical industry, combustion process, transport emission, and solvent usage sources. Although several SBTEX toxic assessment studies have been conducted, they have mainly relied on ambient measurements to estimate exposure and limit their scope to specific locations and observational periods. To overcome these spatiotemporal limitations, an air quality modeling system over the US Gulf region was created, predicting the spatially and temporally enhanced SBTEX modeling concentrations from May to September 2012. Due to the incompleteness of SBTEX in the official US Environmental Protection Agency (EPA) National Emission Inventory (NEI), the Hazardous Air Pollutions Imputation (HAPI) program was used to identify and estimate the missing HAP emissions. The improved emission data were processed to generate the chemically speciated hourly gridded emission inputs for the Comprehensive Air Quality Model with Extensions (CAMx) chemical transport model to simulate the SBTEX concentrations over the Gulf modeling region. SBTEX pollutants were modeled using the Reactive Tracer feature in CAMx that accounts for their chemical and physical processes in the atmosphere. The data show that the major SBTEX emissions in this region are contributed by mobile emissions (45 %), wildfire (30 %), and industry (26 %). Most SBTEX emissions are emitted during daytime hours (local time 14:00–17:00), and the emission rate in the model domain is about 20–40 t h−1, which is about 4 times higher than that in the nighttime (local time 24:00–04:00, about 4–10 t h−1). High concentrations of SBTEX (above 1 ppb) occurred near the cities close to the I-10 interstate highway (Houston, Beaumont, Lake Charles, Lafayette, Baton Rouge, New Orleans, and Mobile) and other metropolitan cities (Shreveport and Dallas). High styrene concentrations were co-located with industrial sources, which contribute the most to the styrene emissions. The HAPI program successfully estimated missing emissions of styrene from the chemical industry. The change increased total styrene emissions by 22 %, resulting in maximum ambient concentrations increasing from 0.035 to 1.75 ppb across the model domain. The predicted SBTEX concentrations with imputed emissions present good agreement with observational data, with a correlation coefficient (R) of 0.75 (0.46 to 0.77 for individual SBTEX species) and a normalized mean bias (NMB) of −5.6 % (−24.9 % to 32.1 % for the individual SBTEX species), suggesting their value for supporting any SBTEX-related human health studies in the Gulf region. The SBTEX data were published at Zenodo (https://doi.org/10.5281/zenodo.7967541) (Wang et al., 2023), and the HAPI tool was also published at Zenodo (https://doi.org/10.5281/zenodo.7987106) (Wang and Baek, 2023).

Unveiling first report on in silico modeling of aquatic toxicity of organic chemicals to Labeo rohita (Rohu) employing QSAR and q-RASAR

Labeo rohita, a fish species within the Carp family, holds significant dietary and aquacultural importance in South Asian countries. However, the habitats of L. rohita often face exposure to various harmful pesticides and organic compounds originating from industrial and agricultural runoff. It is challenging to individually investigate the effects of each potentially harmful compound. In such cases, in silico techniques like Quantitative Structure-Activity Relationship (QSAR) and quantitative Read-Across Structure-Activity Relationship (q-RASAR) can be employed to construct algorithmic models capable of simultaneously assessing the toxicity of numerous compounds. We utilized the US EPA's ToxValDB database to curate data regarding acute median lethal concentration (LC50) toxicity for L. rohita. The experimental variables included study type (mortality), study duration (ranging from 0.25 h to 4 h), exposure route (static, flowthrough, and renewal), exposure method (drinking water), and types of chemicals (industrial chemicals and pharmaceuticals). Using this dataset, we developed regression-based QSAR and q-RASAR models to predict chemical toxicity to L. rohita based on chemical descriptors. The key descriptors for predicting the toxicity of L. rohita in the regression-based QSAR model include F05[S–Cl], SpMax_EA(ri), s4_relPathLength_2, and SpDiam_AEA(ed). These descriptors can be employed to estimate the toxicity of untested compounds and aid in the development of compounds with lower toxicity based on the presence or absence of these descriptors. Both the QSAR and q-RASAR models serve as valuable tools for understanding the chemicals' structural features responsible for toxicity and for filling gaps in aquatic toxicity data by predicting the toxicity of newly untested compounds in relation to L. rohita. Finally, the developed best model was employed to predict 297 external chemicals, the most toxic substances to L. rohita were identified as cyhalothrin, isobornyl thiocyanatoacetate, and paclobutrzol, while the least toxic ones included ethyl acetate, ethylthiourea, and n-butyric acid.

Effect of Demographic and Environmental Factors on Chronic Lymphocytic Leukemia(CLL) in the State of Colorado

Various publications have examined the relationship between environmental risk factors and the development of CLL. Factors such as household income, race, altitude and air pollution have been explored. Results have been inconclusive. In this study, we examine these four factors and their possible relationship to the prevalence of CLL. We accessed the state of Colorado all payer claims database of about 3.6 million people with dates of service from Jan 2017 to June 2020. We calculated age and sex in CLL patients. We used propensity score matching based on age and sex to generate our comparator group on a 1:1 matching scheme. We accessed US EPA 2022 data to get air quality index (AQI) for all zip codes in Colorado and US census data for household income and racial distribution by zip code. We accessed US geological survey data to determine average elevation by zip code. We assess these four factors in relation to CLL and the comparator group. We found 3622 cases of CLL in the total population. The average age of CLL patients was 69 and the sex distribution was 74% male. After propensity matching, we identified an equal number of non CLL patients as the comparator. In analyzing CLL patients versus the comparators, we found no relationship between average elevation, racial makeup, average household income, or air quality by zip code (P=NS). In this large statewide population, there was no effect of race distribution, household income, elevation or air quality on the prevalence of CLL.

The concentrations of polycyclic aromatic hydrocarbons in fish: A systematic review

This study was conducted on the concentrations of PAHs, including benzo[a]pyrene and the sum of four PAHs (benz[a]anthracene, chryseno, benzo[b]fluoranthene, and benzo[a]pyrene), in unsmoked fish tissues. The values were related to the time period, locality (country and region), living habits, eating habits, and types of environments of the fish species. The data obtained has been also compared with the limits established by the United States Environmental Protection Agency (U.S. EPA) and European Union (E.U.) legislation. The data were collected through a PRISMA systematic review (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) from 1982 to 2020. Only documents that presented the PAHs concentration values were selected. China, Nigeria, and Iran had the highest number of studies. The species Coptodon zillii, Siganus punctatus, and Liza abu were the most commonly used bioindicators. Fish inhabiting demersal and pelagic environments showed the highest concentrations of PAHs. The majority of PAH concentrations of the analyzed documents fell within permissible limits for human consumption, representing a total percentage of 79.49 % for benzo[a]pyrene and 82.86 % for the sum of the 4 PAHs. Although some studies identified concentrations of benzo[a]pyrene alone and benzo[a]pyrene, benz[a]anthracene, chryseno, benzo[b]fluoranthene above the legislation limits, in most of them, the concentrations reported in fish tissue were below the limits defined by European Legislation for human consumption.

Heavy Metal Content Characteristics and Pollution Source Analysis of Shallow Groundwater in Tengzhou Coal Mining Area

This study analyzed the sources of total metal elements using the positive matrix factorization (PMF) model and conducted human health risk assessment for adults and children using the health risk assessment model recommended by the United States Environmental Protection Agency (USEPA). According to the health risk assessment, As is the main contributor to the non-carcinogenic risk of groundwater in Tengzhou, with drinking water as the main exposure route. Regarding carcinogenic risks (CR), the values of As and Cr for adults and children were higher than 1 × 10−4, with drinking water as the main exposure route. Therefore, As is the largest contributor to the CR of groundwater for adults and children and drinking water is the main exposure route in the study area. The primary exposure pathways are oral intake and dermal contact, with oral intake presenting a significant risk. The carcinogenic risks according to principal component analysis (PCA) and PMF analysis showed that the main sources of heavy metals in shallow groundwater in Tengzhou City are agricultural, industrial, natural, and industrial deposition sources, with contribution rates of 21.7%, 27.2%, 31.0%, and 20.1%, respectively. In particular, natural sources are the largest contributor to the accumulation of heavy metals.

Deciphering exogenous chemical carcinogenicity through interpretable deep learning: A novel approach for evaluating atmospheric pollutant hazards

Cancer remains a significant global health concern, with millions of deaths attributed to it annually. Environmental pollutants play a pivotal role in cancer etiology and contribute to the growing prevalence of this disease. The carcinogenic assessment of these pollutants is crucial for chemical health evaluation and environmental risk assessments. Traditional experimental methods are expensive and time-consuming, prompting the development of alternative approaches such as in silico methods. In this regard, deep learning (DL) has shown potential but lacks optimal performance and interpretability. This study introduces an interpretable DL model called CarcGC for chemical carcinogenicity prediction, utilizing a graph convolutional neural network (GCN) that employs molecular structural graphs as inputs. Compared to existing models, CarcGC demonstrated enhanced performance, with the area under the receiver operating characteristic curve (AUCROC) reaching 0.808 on the test set. Due to air pollution is closely related to the incidence of lung cancers, we applied the CarcGC to predict the potential carcinogenicity of chemicals listed in the United States Environmental Protection Agency's Hazardous Air Pollutants (HAPs) inventory, offering a foundation for environmental carcinogenicity screening. This study highlights the potential of artificially intelligent methods in carcinogenicity prediction and underscores the value of CarcGC interpretability in revealing the structural basis and molecular mechanisms underlying chemical carcinogenicity.

Occurrence, toxicity load, pollution index and health risk assessment of trace elements in drinking water of two catchments in North-western Himalayas

ABSTRACT The study focuses on the analysis of trace metals in drinking water from the Ganderbal and Budgam districts of Jammu and Kashmir. We have used high-resolution inductively-coupled plasma mass spectrometry (HR-ICP-MS) to measure the concentrations of 31 trace metals in the water samples. The measured concentrations were then compared with the permissible limits set by the United States Environmental Protection Agency (USEPA), Bureau of Indian Standards (BIS), and World Health Organization (WHO). The results of the study indicate that arithmetic mean of several trace elements, including aluminum (Al = 781), chromium (Cr = 139), manganese (Mn = 41.86), nickel (Ni = 25.89), molybdenum (Mo = 1.30), cadmium (Cd = 36.86), and mercury (Hg = 67.65), in µg l−1 were found to have concentrations higher than their respective permissible limits. On the other hand, the arithmetic mean of elements, such as beryllium (Be = 0.14), boron (B = 32.72), iron (Fe = 233), cobalt (Co = 1.79), copper (Cu = 10.71), arsenic (As = 0.93), selenium (Se = 3.13), strontium (Sr = 257), zinc (Zn = 43), antimony (Sb = 1.44), barium (Ba = 28.56), gold (Au = 0.91), and lead (Pb = 0.91) in µg l−1, had concentrations below the permissible limits recommended by USEPA, BIS, and WHO. To assess the toxicity of the heavy metals in the study area, we calculated the Heavy Metal Toxicity Load (HMTL) for each metal. Based on these calculations, we concluded that only cadmium (Cd) and chromium (Cr) need to be removed from drinking water to ensure safety. The study also conducted a health risk assessment for children and adults based on the measured concentrations of heavy metals. The assessment considered the ingestion and dermal contact routes of exposure. The Hazard Index (HI), which indicates the non-carcinogenic health effects, exceeded unity for only one element, cadmium (Cd), in the children and adult groups. This suggests potential non-carcinogenic health risks associated with the ingestion of water and dermal contact. Additionally, the potential carcinogenic risk of cadmium (Cd) and arsenic (As) was identified and recommended for further attention. The study further evaluated the Heavy Metal Pollution Index (HPI) to assess the overall quality of drinking water in the study area. The HPI results indicated that the quality of drinking water was good, and the pollution levels in the study area were low. Overall, the findings of this study provide valuable information for water resource development and supply agencies. The results can be used as a baseline for future research and monitoring efforts in the region.

Determination of hexavalent chromium in textiles of daily use by ion chromatography and dermal risk assessment

The determination of hexavalent chromium in textiles and clothes is challenging since during extraction, the original oxidation state should not be altered. Since, as a matter of fact, current analytical methods are focused only on total chromium determination, the purpose of this research is to develop a reliable analytical method for the determination of Cr(VI) in textiles and tissues of daily use for a reliable application of risk analysis models, which are usually based on total Cr data.After optimization, a 0.0025 M Na3PO4 extraction solution was selected for the extraction of Cr(VI) from textiles. This solution minimizes possible interconversion redox reactions and interference, and provides good extraction recoveries (88.4 ± 2.5% - 105.5 ± 0.6 %, according to Cr(VI) concentration) and quantitation limits (0.017 mg/kg), fully complying the current limits set for Cr(VI) in textiles in contact with skin, and for leachable Cr(VI).The developed method was validated investigating intra-day repeatability (n = 10) and inter-day repeatability (n = 30) which were below 12%, and matrix effect which was below 6% confirming the precision of the method and the negligibility of a matrix interference during the whole analysis. The method, which was proved to be suited also for bioaccessibility studies in saliva and sweat, was applied to the analysis of tank top, coloured paper napkin, polyamide tights, panties, highlighting Cr(VI) content in the panties only at very low concentration (0.028 mg/kg). As verified by ECHA and US EPA approaches, this amount does not pose a non-carcinogenic risk for human health. As regards carcinogenic risk, considering both adult and child exposure, the dermal contact with the panties poses an acceptable risk (R ≤ 10−6).

Determination of Heavy Metals in Municipal Water Network of Tehran, Iran: A Health Risk Assessment with a Focus on Carcinogenicity

Background: Several contaminants such as trace elements can pollute drinking water sources with subsequent toxic effects on humans. These compounds may also accumulate in target organs and result in carcinogenic reactions. Objectives: The concentrations of heavy metals, including arsenic (As), nickel (Ni), zinc (Zn), aluminum (Al), copper (1), cobalt (Co), lead (Pb), cadmium (Cd), iron (Cd), tin (2), antimony (Sb), chromium (3), and mercury (Hg) were aimed to determine in the drinking water of Tehran, Iran and to assess the carcinogenic and non-carcinogenic risk for consumers. Methods: A total of 66 tap water samples were collected from 22 regions of Tehran and their heavy metal contents were measured by inductively coupled plasma mass spectrometry (ICP-MS). The non-carcinogenic and carcinogenic health risks were calculated, using hazard quotient (HQ) and incremental lifetime cancer risk (ILCR), respectively. Results: The findings revealed that the mean concentrations of measured elements were lower than the maximum permissible limits established by Iranian National Standards, United States Environmental Protection Agency (USEPA), and the World Health Organization (WHO). HQ was less than 1 for all metals except Cr and ILCR was higher than 1× 10-4 for Cr and Cd, which may cause human health risk. Conclusions: No carcinogenic effects were posed by heavy metals contamination in the drinking water of Tehran; however, the content of Cr and Cd may cause human health risks because of the high daily intake of tap water throughout the lifetime and the tendency of these metals to accumulate in the human body organs. Therefore, implementing ongoing programs to monitor heavy metals in municipal drinking water and applying appropriate corrective actions to prevent the transfer of these pollutants to drinking water is crucial.

Study on the Biotoxicity, Microbial Degradation and Metabolism, and Solidification of Monoaromatic Hydrocarbons (MACHs)

Monoaromatic hydrocarbons (MACHs), also known as aromatic organic compounds, are a general term for benzene and its derivatives. In a broad sense, monoaromatic hydrocarbons include all aromatic compounds. It can be used as an organic solvent in building decoration materials and is also widely used in other industries such as dye manufacturing, rubber manufacturing, pharmaceutical industry, pesticide industry, etc. Therefore, monoaromatic hydrocarbons are common pollutants emitted by human activities and can be widely detected in human living and living environments. With the development of China's urban economy, the improvement of residents' living standards, and the rapid increase in the number of motor vehicles, the pollution of monoaromatic hydrocarbons has become increasingly severe. Monoaromatic hydrocarbons have strong carcinogenic effects and can directly harm human respiratory, hematopoietic, nervous, reproductive and other system organs. Monoaromatic hydrocarbons also have high photochemical reactivity and are closely related to the formation of photochemical smog and aerosols in the atmosphere. Moreover, monoaromatic hydrocarbons have the characteristics of wide pollution sources, long action time, high pollution concentration, and long release cycle. They have been prioritized by the United States Environmental Protection Agency (USEPA) as pollutants for control, and have also been included in China's "blacklist" of environmental priority pollutants.

Combination of computational new approach methodologies for enhancing evidence of biological pathway conservation across species

The ability to predict which chemicals are of concern for environmental safety is dependent, in part, on the ability to extrapolate chemical effects across many species. This work investigated the complementary use of two computational new approach methodologies to support cross-species predictions of chemical susceptibility: the US Environmental Protection Agency Sequence Alignment to Predict Across Species Susceptibility (SeqAPASS) tool and Unilever's recently developed Genes to Pathways – Species Conservation Analysis (G2P-SCAN) tool. These stand-alone tools rely on existing biological knowledge to help understand chemical susceptibility and biological pathway conservation across species. The utility and challenges of these combined computational approaches were demonstrated using case examples focused on chemical interactions with peroxisome proliferator activated receptor alpha (PPARα), estrogen receptor 1 (ESR1), and gamma-aminobutyric acid type A receptor subunit alpha (GABRA1). Overall, the biological pathway information enhanced the weight of evidence to support cross-species susceptibility predictions. Through comparisons of relevant molecular and functional data gleaned from adverse outcome pathways (AOPs) to mapped biological pathways, it was possible to gain a toxicological context for various chemical-protein interactions. The information gained through this computational approach could ultimately inform chemical safety assessments by enhancing cross-species predictions of chemical susceptibility. It could also help fulfill a core objective of the AOP framework by potentially expanding the biologically plausible taxonomic domain of applicability of relevant AOPs.

Dual-functional DNAzyme powered CRISPR-Cas12a sensor for ultrasensitive and high-throughput detection of Pb2+ in freshwater

Freshwater lead pollution has posed severe threat to the environment and human health, underscoring the urgent necessity for accurate and user-friendly detection methods. Herein, we introduce a novel Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR-Cas) sensor for highly sensitive Pb2+ detection. To accomplish this, we designed a dual-functional deoxyribozyme (df-DNAzyme) probe that functions as an activator for the CRISPR-Cas12a system while also recognizing Pb2+. The df-DNAzyme probe was subsequently combined with gold nanoparticles (AuNPs) to fabricate a DNAzyme/AuNP nanoprobe, facilitating the activation of CRISPR-Cas12a in a one-to-multiple manner. Upon exposure to Pb2+, the df-DNAzyme is cleaved, causing disintegration of the DNAzyme/AuNP nanoprobe from magnetic beads. The degraded DNAzyme/AuNP containing multiple double-stranded DNA activators efficiently triggers CRISPR-Cas12a activity, initiating cleavage of fluorescence-quenched reporter DNA and generating amplified signals accordingly. The amplified fluorescence signal is accurately quantified using a quantitative polymerase chain reaction (qPCR) instrument capable of measuring 96 or 384 samples simultaneously at the microliter scale. This technique demonstrates ultra-sensitive detection capability for Pb2+ at concentrations as low as 1 pg/L within a range from 1 pg/L to 10 μg/L, surpassing limits set by World Health Organization (WHO) and United States Environmental Protection Agency (US EPA) guidelines. This study offers an ultrasensitive and high-throughput method for the detection of Pb2+ in freshwater, thereby advancing a novel approach towards the development of precise and convenient techniques for detecting harmful contaminants.

Evaluation of the Radon Levels in the Groundwater Wells of Qatar: Radiological Risk Assessment

The objective of this work is to give a holistic overview of the groundwater quality in Qatar in terms of its radon levels and provide a radiological risk assessment of elevated radon levels on human health. This study covered the analysis of groundwater collected from various locations throughout Qatar and maps using ArcGIS followed by a radiological risk assessment of radon in Qatar. There is no extensive study reported to investigate radon activity levels in groundwater across Qatar and their health effects. The radon level measurements of the Qatari groundwater ranged between 2.7 ± 0.2 and 60.7 ± 13.4 Bq/L with a mean value of 20.6 Bq/L, which is greater than the US EPA’s maximum contamination level (11 Bq/L). About 65% of the studied samples exceeded the US EPA’s MCL guidelines. The mean total annual effective dose due to radon inhalation and ingestion was 0.056 mSv/y, which is below the WHO reference level of 0.1 mSv/y. The radon radiological risk study through inhalation and ingestion clearly revealed that the contribution of the inhalation dose was higher than the ingestion dose.