Environmental Protection Agency Research Articles

Evaluation of environmental impact assessment and mitigation strategies for Gulpur hydropower project, Kotli, Pakistan

AbstractEnvironmental Impact Assessment (EIA) became mandatory in Pakistan in 1983 with the passage of the Pakistan Environmental Protection Ordinance. The Sustainable Development Goals were incorporated into Pakistan's national development strategy, making it the first country in history to do so. The study is based on evaluating the mitigation strategies and environmental impact assessment at the Gulpur Hydropower Project (HPP), Kotli, AJK, which uses the Poonch River's water resources to generate power and has a design capacity of 100 MW using the EIA documentation of Gulpur HPP. In addition to making additional observations and reviewing the literature, the study looked at Mira Power Limited's EIA reports. The possible effects, as well as the Government's and MPL's mitigating actions, were examined by the authors. EIA procedures at the Gulpur HPP considered several laws, including the Pakistan Environmental Protection Agency, AJK Wildlife Ordinance of 2013, the Land Acquisition Act of 1894, and Laws Regulating Flow Releases for Hydropower Projects. Projects using hydropower in delicate areas carry a high risk. Given the thorough analysis of the hazards in this instance, it is evident that the EIA had a significant impact on the project's design. The authors concluded that there are no negative environmental effects of the construction of hydropower projects in the concerned area and that all potential effects and compensation were handled legally and efficiently. The study suggested that all hydropower projects in Pakistan undertake environmental impact assessments.

Towards transparent and durable copper-containing antimicrobial surfaces

Metallic copper is a potent antimicrobial agent with high efficacy against a range of microorganisms. Whilst it is commonplace for objects such as door handles and hospital bedrails to be made of or to be coated with copper, other high-touch surfaces such as those of screens and monitors would lose their optical transparency. Herein, we report the design of a transparent antimicrobial nanostructured copper surface obtained by dewetting ultrathin metal copper films on glass. Antimicrobial effectiveness of >99.9 % was obtained within 2 h against Staphylococcus aureus following the US Environmental Protection Agency Test method. Moreover, the proposed surfaces show an average transmittance between 70–80% with little color in the visible range. Additionally, they maintain optical and antimicrobial properties after abrasion and chemical exposure tests designed to replicate physical wear and repeated exposure to biocidal cleaning materials. With the demonstrated surfaces’ antimicrobial, colorless, and durability properties, they have potential in applications such as touch-enabled public or personal displays once higher transparency is achieved.

Pregnancy exposure to PM2.5 from wildland fire smoke and preterm birth in California

BackgroundWildfires in the Western United States are a growing and significant source of air pollution that is eroding decades of progress in air pollution reduction. The effects on preterm birth during critical periods of pregnancy are unknown. MethodsWe assessed associations between prenatal exposure to wildland fire smoke and risk of preterm birth (gestational age < 37 weeks). We assigned smoke exposure to geocoded residence at birth for all live singleton births in California conceived 2007–2018, using weekly average concentrations of particulate matter ≤ 2.5 µm (PM2.5) attributable to wildland fires from United States Environmental Protection Agency’s Community Multiscale Air Quality Model. Logistic regression yielded odds ratio (OR) for preterm birth in relation to increases in average exposure across the whole pregnancy, each trimester, and each week of pregnancy. Models adjusted for season, age, education, race/ethnicity, medical insurance, and smoking of the birthing parent. ResultsFor the 5,155,026 births, higher wildland fire PM2.5 exposure averaged across pregnancy, or any trimester, was associated with higher odds of preterm birth. The OR for an increase of 1 µg/m3 of average wildland fire PM2.5 during pregnancy was 1.013 (95 % CI:1.008,1.017). Wildland fire PM2.5 during most weeks of pregnancy was associated with higher odds. Strongest estimates were observed in weeks in the second and third trimesters. A 10 µg/m3 increase in average wildland fire PM2·5 in gestational week 23 was associated with OR = 1.034; 95 % CI: 1.019, 1.049 for preterm birth. ConclusionsPreterm birth is sensitive to wildland fire PM2.5; therefore, we must reduce exposure during pregnancy.

Health risk assessments of heavy metals and trace elements exposure in the breast milk of lactating mothers in the Northeastern Iran.

Mother's breast milk is a natural and complete food for infants but can be a main source of exposure to toxic pollutants. These pollutants can negatively affect the health of the infant. Therefore, conducting biomonitoring surveys is essential to evaluate such health effects in toxicological research. This study aimed to estimate the probable health risks for infants exposed to essential and non-essential trace elements through breast milk ingestion. This descriptive-analytical, cross-sectional study was performed on 90 breastfeeding mothers referred to the health centers in Mashhad, Iran in January 2021. The health risk assessments (carcinogenic and non-carcinogenic risk) were estimated using chronic daily intake (CDI), hazard quotient (HQ), hazard index (HI), and lifetime carcinogenic risk (CR), which were recommended by the US Environmental Protection Agency (US EPA). The results of the HQ values of trace elements through ingestion exposure for arsenic (90%), copper (90%), zinc (40%), and iron (10%) exceeded the threshold of HQ, and arsenic (66.59%), copper (16.91%), and zinc (9.68%) and iron (4.57%) had the highest contribution to increasing the HI index. The average value of CR was 5. 08 × 10-3. Chromium and iron showed significant relationships (P<0.05) with education level and disease background in this study, and the concentration of chromium, iron, and zinc in the breast milk samples significantly changed during lactation stages (P<0.05). Overall, the risk of carcinogenicity through exposure to breast milk for infants was higher than the safety level of US EPA risk. Therefore, there could be a potential health risk of trace elements, particularly arsenic, copper, and zinc for infants in Mashhad, Iran through the consumption of mothers' breast milk. More efforts are required to control and reduce routes of receiving trace elements in breastfeeding mothers by the competent authorities.

Hollow sphere CuCo2O4 as highly efficient catalyst of microwave-assisted Fenton-like reaction for water treatment

In industries with high-value addition, the demand for rapid pollutant breakdown through advanced water treatment techniques is growing. The microwave (MW)-assisted Fenton-like reaction is notable for its exceptionally fast reaction rate, providing enhanced economic benefits, especially in the context of limited factory space. In this research, hollow sphere-shaped CuCo2O4 was synthesized at the various temperature (200 °C, 250 °C, 300 °C, 350 °C, 400 °C, 450 °C, and 500 °C) and used in a MW-assisted Fenton-like reaction to break down the organic model compound, methyl orange (MO). Unlike typical Fenton reactions that are most effective in acidic conditions (around pH 3), the synthesized CuCo2O4 in this study demonstrated its highest efficiency at a circumneutral pH level (pH 6). It was observed that the majority of MO was oxidized by ∙OH within just 3.5 min under the optical condition (10 mg/L MO, 300 mg/L H2O2, 200 mg/L catalyst, pH 6, 20 °C, 200 W, and total volume of 50 mL). Ex-situ analysis confirmed the gradual generation of oxygen vacancies (OV) with each repeated cycle. The formation of OV enhances the catalyst's MW absorption and oxidation potential, resulting in the superior MO decomposition performance even after the 5th cycle. Although there were minor changes in the shell thickness and smoothness, along with some leaching (1.17 mg Cu/L and 0.01 mg Co/L per cycle), the catalyst continued to comply with the US Environmental Protection Agency (EPA) guidelines for drinking and discharge water.

Risk of dementia due to Co-exposure to air pollution and neighborhood disadvantage

BackgroundCo-exposure to air pollution and neighborhood disadvantage may influence cognition decline. We tested these associations in the context of dementia risk. MethodsWe leveraged a cohort of adults ≥65 years (n = 5397) enrolled from 2011 to 2018 in the National Health and Aging Trends Study (NHATS). Particulate matter (PM) ≤ 10 μm in diameter, PM ≤ 2.5 μm in diameter, carbon monoxide, nitric oxide, and nitrogen dioxide - and neighborhood disadvantage were tested for joint associations with dementia risk. Pollutant concentrations at the 2010 census tract level were assigned using the US Environmental Protection Agency's Community Multiscale Air Quality Modeling System. Neighborhood disadvantage was defined using the tract Social Deprivation Index (SDI). Dementia was determined through self- or proxy-report or scores indicative of “probable dementia” according to NHATS screening tools. Joint effects of air pollutants and SDI were tested using quantile g-computation Cox proportional hazards models. We also stratified joint air pollution effects across SDI tertiles. Analyses adjusted for age at enrollment, sex, education, partner status, urbanicity, income, race and ethnicity, years at residence, census segregation, and census region. ResultsSDI score (aHR = 1.08; 95% CI 0.96, 1.22), joint air pollution (aHR = 1.03, 95% CI 0.92, 1.16) and joint SDI with air pollution (aHR = 1.04, 95% CI 0.89, 1.22) were not associated with dementia risk. After accounting for competing risk of death, joint SDI with air pollution was not associated with dementia risk (aHR = 1.06; 95% CI 0.87, 1.29). In stratified models, joint air pollution was associated with greater risk of dementia at high (aHR = 1.19; 95% CI 0.87, 1.63), but not at medium or low SDI. ConclusionAir pollution was associated with greater dementia risk in disadvantaged areas after accounting for competing risks. Air pollution associations with dementia incidence may be attenuated when other risk factors are more prominent in disadvantaged neighborhoods.

Toxic air pollution and concentrated social deprivation are associated with low birthweight and preterm Birth in Louisiana * *K T and G S provide scientific support to communities engaged in environmental advocacy, including litigation, through their work at the Tulane Environmental Law Clinic. They receive no compensation for this work outside of employment. M W declares that she has nothing

Previous studies indicate that pollution exposure can increase risks of adverse birth outcomes, but Black communities are underrepresented in this research, and the potential moderating role of neighborhood context has not been explored. These issues are especially relevant in Louisiana, which has a high proportion of Black residents, an entrenched history of structural racism, the most pounds of toxic industrial emissions annually, and among the nation’s highest rates of low birthweight (LBW), preterm birth (PTB), and infant mortality. We investigated whether air pollution and social polarization by race and income (measured via the index of concentration at the extremes [ICE]) were associated with LBW and PTB among Louisiana census tracts (n = 1101) using spatial lag models. Data sources included 2011–2020 birth records, U.S. Census Bureau 2017 demographic data, and 2017 respiratory hazard (RH) from the U.S. Environmental Protection Agency. Both RH and ICE were associated with LBW (z = 4.4, P < 0.0001; z = −27.0, P < 0.0001) and PTB (z = 2.3, P = 0.019; z = −16.7, P < 0.0001), with no interaction. Severely polluted tracts had 25% higher and 36% higher risks of LBW and PTB, respectively, versus unpolluted tracts. On average, 2166 low birthweight and 3583 preterm births annually were attributable to pollution exposure. Tracts with concentrated social deprivation (i.e. low ICE scores) had 53% higher and 34% higher risks of LBW and PTB, respectively, versus intermediate or mixed tracts. On average, 1171 low birthweight and 1739 preterm births annually were attributable to concentrated deprivation. Our ecological study found that a majority of adverse birth outcomes in Louisiana (i.e. 67% of LBW and PTB combined) are linked to air pollution exposure or disadvantage resulting from social polarization. These findings can inform research, policy, and advocacy to improve health equity in marginalized communities.

Susceptibility of Bemisia tabaci (Hemiptera: Aleyrodidae) Adult Populations to Imidacloprid in Georgia, USA

Abstract Imidacloprid has been one of the most widely used insecticides for managing the sweetpotato whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) in the United States since the U.S. Environmental Protection Agency first registered it in 1994. A major whitefly control failure occurred in the state of Georgia in 2017 when B. tabaci–induced economic losses in horticultural and field crops surpassed approximately US$160 million. Vegetable growers have historically used imidacloprid for whitefly management, which likely led to the insecticide control failures of whiteflies in spring vegetables. Despite this, only a single site documentation of imidacloprid resistance in adults from 2007 in Georgia exists, making the current status unknown. Thus, it is likely that Georgia has an ongoing risk of imidacloprid-resistant B. tabaci infestations. No multicounty, extensive survey for imidacloprid dose response in whitefly exists for the state of Georgia. Therefore, an adult mortality bioassay of a range of imidacloprid concentrations was used to evaluate B. tabaci populations from several counties in South Georgia, where most of these economic losses occurred. This included a maximum dose concentration representing the current highest labeled rate. Dose response to the insecticide was not uniform across locations, with whiteflies in several areas displaying unexpected susceptibility to imidacloprid. Median lethal concentrations (LC50s) ranging from 0.02 to 196.05 mg of active ingredient per liter in Georgia whitefly populations were substantially lower than the reference Florida whitefly population. This baseline information for the state is critical to future evaluations of this insecticide in resistance management programs.

Physico-Chemical Parameters and Bacteriological Quality Assessment of Some Domestic Water Sources in Pankshin LGA of Plateau State Nigeria

Due to human activity and other natural influences, drinking water is seldom found in 100% pure forms in nature. Drinking polluted water is a major source of sickness in underdeveloped nations. The United States Environmental Protection Agency (USEPA) and standard methodologies for the investigation of water and wastewater were followed in the analysis of the collected water samples, which were conducted using automated instrumental methods. The obtained results indicated that the samples used had the following ranges of concentrations: SO42- ranges from ND to 19.00 mg/L; NO3- ranges from 4.40 to 100.32 mg/L; PO42- from 2.02-11,34 mg/L; pH 6.64 to 7.70; Cd from 0.0020 ± 0.001 to 0245 ± 0.01 mg/L; Ni, from 0.0074 ± 0.003 to 0.848 ± 0.021 mg/L; Cr, ND to 0.386 ± 0.082 mg/L; Pb ND to 0.428 ± 0.003 mg/L; total bacteria count TaBC, 4 x 102 to 3.3 x 104 CFU/mL. Most of the physicochemical parameters were above acceptable limits. The bacteriological study of the water samples also revealed that the water samples were all polluted with bacteria and coliforms. From the foregoing, these drinking water sources, therefore require treatment before consumption to minimize or avoid the incidences of water-related diseases.

Per- and Polyfluoroalkyl Substance Exposure Risks in US Carceral Facilities, 2022.

Objectives. To assess the US incarcerated population's risk of exposure to per- and polyfluoroalkyl substances (PFASs). Methods. We assessed how many of the 6118 US carceral facilities were located in the same hydrologic unit code watershed boundaries as known or likely locations of PFAS contamination. We conducted geospatial analyses on data aggregated from Environmental Protection Agency databases and a PFAS site tracker in 2022 to model the hydrologically feasible known and presumptive PFAS contamination sites for nearly 2 million incarcerated people. Results. Findings indicate that 5% (∼310) of US carceral facilities have at least 1 known source of PFAS contamination in the same watershed boundary and that it is at a higher elevation than the facility; also 47% (∼2285) have at least 1 presumptive source. A minimum of 990 000 people are incarcerated in these facilities, including at least 12 800 juveniles. Exposure risks faced by incarcerated youths are disproportionately underassessed. Conclusions. The long-term impacts from potential exposures to PFAS are preventable and exacerbate health inequities among incarcerated populations. Widespread public attention to PFASs can be parlayed into broader environmental monitoring for imprisoned people. (Am J Public Health. 2024;114(5):501-510. https://doi.org/10.2105/AJPH.2024.307571).

Distribution of nitrate/nitrite and toxic metals in the soil-potato system and its health risk assessment in Iran.

Potato is one of the essential food products whose health quality is greatly influenced by soil contamination and properties. In the current study, we have investigated the physicochemical characteristics of agricultural areas and the accumulation of nitrite/nitrate and metals in potato products in Hamedan, Iran. After determining the physicochemical characteristics of soil samples from four agricultural regions of Hamedan, 48 potato samples were collected from these regions. The heavy metals and nitrate/nitrite content were determined by ICP-OES and calorimetric methods, respectively. A negative correlation was observed between soil pH changes with nitrite/nitrate content and the accumulation of some heavy elements in potatoes. Furthermore, a positive correlation was found between soil phosphorus content and lead accumulation in potato. In present study, the amounts of lead, nitrate, and nitrite in 83.3%, 56%, and 12% of the collected samples were higher than the permissible limit reported by the World Health Organization (WHO), respectively. The EDI range for nitrate and nitrite was determined to be 130-260 and 1.4-2.7µg/kg/day, respectively, which is much lower than the RfD set by the US Environmental Protection Agency (USEPA) for nitrite and nitrate. Among metal pollutants, the toxic risk caused by lead in potato consumers was higher than the threshold limit. In conclusion, our findings showed that the physicochemical characteristics of the soil could effectively increase the availability of metal pollutants and nitrite/nitrate to the potato product and significantly reduce its health quality. Therefore, monitoring these pollutants in the soil-potato system, preventing the entry of industrial wastewater, and managing the use of agricultural fertilizers can effectively improve the health of this product for consumers.

Pet collars containing tetrachlorvinphos (TCVP): evaluation of the results of torsion and on-animal release studies and implications for post-application consumer exposure and risk analysis

ABSTRACT Tetrachlorvinphos (TCVP) is the pesticidal active ingredient found in some flea and tick collars for dogs and cats. Recent studies sponsored by The Hartz Mountain Corporation, confirm the safety of TCVP as an active ingredient in pet collars. Based upon data from these new studies and results previously relied upon by the U.S. Environmental Protection Agency, the following conclusions have been made: Torsion study data clearly indicate that approximately 93% of released formulation from TCVP containing pet collars is in a liquid phase immediately following activation. Further, even more relevant to human health risk analysis associated with post-application exposures, in vivo data from dogs wearing TCVP pet collars definitively document that TCVP dust released from the collar is rapidly absorbed into the sebum. The maximum ratio of dust to liquid was 0.023% dust to 99.977% liquid. In vivo fur data provide scientific evidence confirming that the mechanism of dissemination of TCVP from pet collars is as a liquid suspended or dissolved in the animal’s sebum, even though it may be released from the collar as a solid. Thus, potential post-application exposure to TCVP, including immediately following collar placement, is almost entirely to a liquid phase. Based upon EPA’s refined and conservative “untrimmed” collar risk assessment, post-application incidental oral hand-to-mouth activity by children aged 1 to <2 years of age results in margins of exposure significantly greater than the level of concern of 1000, and therefore do not present unreasonable health risk.

Geographical distribution of radon and associated health risks in drinking water samples collected from the Mulazai area of Peshawar, Pakistan

Geospatial methods, such as GIS and remote sensing, map radon levels, pinpoint high-risk areas and connect geological traits to radon presence. These findings direct health planning, focusing tests, mitigation, and policies where radon levels are high. Overall, geospatial analyses offer vital insights, shaping interventions and policies to reduce health risks from radon exposure. There is a formidable threat to human well-being posed by the naturally occurring carcinogenic radon (222Rn) gas due to high solubility in water. Under the current scenario, it is crucial to assess the extent of 222Rn pollution in our drinking water sources across various regions and thoroughly investigate the potential health hazards it poses. In this regard, the present study was conducted to investigate the concentration of 222Rn in groundwater samples collected from handpumps and wells and to estimate health risks associated with the consumption of 222Rn-contaminated water. For this purpose, groundwater samples (n = 30) were collected from handpumps, and wells located in the Mulazai area, District Peshawar. The RAD7 radon detector was used as per international standards to assess the concentration of 222Rn in the collected water samples. The results unveiled that the levels of 222Rn in the collected samples exceeded the acceptable thresholds set by the US Environmental Protection Agency (US-EPA) of 11.1 Bq L−1. Nevertheless, it was determined that the average annual dose was below the recommended limit of 0.1 mSv per year, as advised by both the European Union Council and the World Health Organization. In order to avoid the harmful effects of such excessive 222Rn concentrations on human health, proper ventilation and storage of water in storage reservoirs for a long time before use is recommended to lower the 222Rn concentration.

Optimization of benzene exposure risk assessment: An integrated approach utilizing internal and external concentrations with a focus on biomarkers S-PMA & t, t-MA

In the majority of occupational settings within China, the concentrations of benzene are observed to fall markedly below the demarcated detection thresholds. Employing traditional risk assessment models, the presence of exceptionally low airborne benzene exposure concentrations may infuse heightened degrees of uncertainty. Consequently, the necessity arises to investigate risk assessment methodologies more apt for the prevalent exposure environment among employees. In the present study, a pharmacokinetic model premised on urinary benzene metabolites (S-PMA and t, t-MA) was employed to ascertain a more precise daily airborne benzene exposure concentration per individual. This value was integrated into the linear multistage model as the ‘internal exposure concentration’. In conjunction with the U.S National Environmental Protection Agency's (EPA) inhalation risk assessment model predicated on the external exposure concentration, the Singapore Ministry of Manpower's (MOM) model, and the linear multistage (LMS) model, the carcinogenic and non-carcinogenic effects of benzene were evaluated for 1781 benzene-exposed employees across 76 enterprises in Jiangsu Province. Findings suggest that in the linear multilevel model assessment, the cancer risk levels based on t, t-MA and S-PMA were higher in the printing and recording media reproduction industry, automobile manufacturing industry, general equipment manufacturing industry and the furniture manufacturing industry (median 2.842 × 10−4, 2.819 × 10−4, 2.809 × 10−4, and 2.678 × 10−4), which align more consistently with the actual benzene exposure circumstances of each industry's study participants, with overall risk levels calculated by the linear multistage model exceeding those of the EPA inhalation risk assessment model and the MOM model. This implies that the linear multistage model of internal exposure, based on the reciprocal of benzene biomarkers S-PMA and t, t-MA for airborne benzene exposure, presents enhanced sensitivity and suitability for the current occupational health risk assessment of workers. Without doubt, biomarker-based benzene exposure risk assessment emerges as the optimal choice.

An approach of radiological impact analysis due to a simulated accident of the TRIGA research reactor of Bangladesh

The present study focused on the radiological impact analysis by assessing radiological doses due to a postulated TRIGA Mark-II research reactor accident at AERE, Savar, Dhaka, Bangladesh. Core inventory and source term of radionuclides from different groups such as noble gas, halogen, tellurium, alkali metal, lanthanide, alkaline earth metal, cerium and transition metal were analyzed for 365 days of operation at full power (3 MWth) due to a postulated nuclear accident. The HotSpot code was used for the dose calculation, and the dose values of TED, and Thyroid were calculated for a 40 km radius from the reactor site. Local meteorological data from Bangladesh Meteorological Department were used for the dose assessment and doses were calculated in the three dominant directions such as South, Southeast, and West. The TED and Thyroid dose values are assessed and compared to the PAZs dose criteria of the U.S. Environmental Protection Agency. It is found that doses are higher in stability class F, and evacuation, sheltering, and iodine prophylaxis are needed at longer distances. Since outside of the AERE campus is densely populated, these calculated data may help to ensure radiological safety by taking required protective actions like evacuation, sheltering, and iodine tablet consumption for the same type of accidental situation.

Evaluation of the environmental quality monitoring protocol for Amazonian streams: a systematic review

The Amazon Rainforest is renowned for its extraordinary biodiversity and the ravages of pervasive deforestation. The removal of natural vegetation significantly affects Amazonian streams, leading to alterations in their environmental conditions. In the United States, the Environmental Protection Agency has devised a comprehensive protocol to monitor changes in the environmental quality of streams. Since 2011, the Sustainable Amazon Network has implemented this protocol in Amazonian streams. Our systematic review aimed to address the following questions: i) How widely has the protocol been employed in Amazonian streams?; ii) Is the utilization of this protocol well-distributed across the Amazon Basin?; iii) Which types of land use have been assessed using this protocol?; iv) Which components of the aquatic biota have been studied in conjunction with the protocol?; and, v) Which metrics of the protocol are most crucial for elucidating aquatic biota distribution? We conducted searches using the Web of Science and Google Scholar databases, identifying 34 studies that directly aligned with our objectives. It was observed that the Eastern Amazon had the highest number of streams evaluated. Additionally, aquatic insects emerged as an effective tool when utilized alongside the protocol for evaluating the impacts of changes in land use. Ultimately, the most important metrics for assessing impacts on aquatic biota were shelter availability in the channels, the preservation status of riparian forests, and water quality. We recommend developing a simplified version of this protocol to facilitate its application for research teams with limited personnel and financial resources available for fieldwork. Keywords: aquatic conservation, biomonitoring, land use change, sampling efficiency, stream ecology.

Considering a Utility-Centric Framework Based on "Minimum Orthophosphate" Criteria for Mitigation of Elevated Cuprosolvency in Drinking Water.

Gaps in the United States Environmental Protection Agency (US EPA) Lead and Copper Rule (LCR) leave some consumers and their pets vulnerable to high cuprosolvency in drinking water. This study seeks to help proactive utilities who wish to mitigate cuprosolvency problems through the addition of orthophosphate corrosion inhibitors. The minimum doses of orthophosphate necessary to achieve acceptable cuprosolvency in relatively new copper pipe were estimated as a function of alkalinity via linear regressions for the 90th, 95th, and 100th percentile copper tube segments (R2 > 0.98, n = 4). Orthophosphate was very effective at reducing cuprosolvency in the short term but, in some cases, resulted in higher long-term copper concentrations than the corresponding condition without orthophosphate. Alternatives to predicting "long-term" results for copper tubes using simpler bench tests starting with fresh Cu(OH)2 solids showed promise but would require further vetting to overcome limitations such as maintaining water chemistry and orthophosphate residuals and to ensure comparability to results using copper tube.

Optimizing androgen receptor prioritization using high-throughput assay-based activity models.

Introduction: Computational models using data from high-throughput screening assays have promise for prioritizing and screening chemicals for testing under the U.S. Environmental Protection Agency's Endocrine Disruptor Screening Program (EDSP). The purpose of this work was to demonstrate a data processing method for the determination of optimal minimal assay batteries from a larger comprehensive model, to provide a uniform method of evaluating the performance of future minimal assay batteries compared with the androgen receptor (AR) pathway model, and to incorporate chemical cluster analysis into this evaluation. Although several of the assays in the AR pathway model are no longer available through the original vendor, this approach could be used for future evaluations of minimal assay models for prioritization and screening. Methods: We compared two previously published models and found that an expanded 14-assay model had higher sensitivity for antagonists, whereas the original 11-assay model had slightly higher sensitivity for agonists. We then investigated subsets of assays in the original AR pathway model to optimize overall testing strategies that minimize cost while maintaining sensitivity across a broad chemical space. Results and Discussion: Evaluation of the critical assays across subset models derived from the 14-assay model identified three critical assays for predicting antagonism and two critical assays for predicting agonism. A minimum of nine assays is required for predicting agonism and antagonism with high sensitivity (95%). However, testing workflows guided by chemical structure-based clusters can reduce the average number of assays needed per chemical by basing the assays selected for testing on the likelihood of a chemical being an AR agonist, according to its structure. Our results show that a multi-stage testing workflow can provide 95% sensitivity while requiring only 48% of the resources required for running all assays from the original full models. The resources can be reduced further by incorporating in silico activity predictions. Conclusion: This work illustrates a data-driven approach that incorporates chemical clustering and simultaneous consideration of antagonism and agonism mechanisms to more efficiently screen chemicals. This case study provides a proof of concept for prioritization and screening strategies that can be utilized in future analyses to minimize the overall number of assays needed for predicting AR activity, which will maximize the number of chemicals that can be tested and allow data-driven prioritization of chemicals for further screening under the EDSP.

Monitoring ammonia concentrations in more than 10 stations in the Po Valley for the period 2007–2022 in relation to the evolution of different sources

Regarding secondary aerosols, in addition to the significant contribution of anthropogenic gases such as NOx and SO2, atmospheric ammonia (NH3) plays a crucial role as the primary basic gaseous species capable of neutralizing acidic compounds. This acid–base reaction is responsible for the formation of ammonium nitrate (NH4NO3), constituting up to 60% of PM10 within the Po River basin in Italy. Ion chromatographic analyses performed on offline samples indicate that this secondary inorganic species exhibits minimal concentration variability over the Po Valley because of limited air circulation due to orography and mesoscale air circulation. Therefore, investigating gaseous precursors becomes crucial. From the northern to the southern part of Lombardy—the region at the center of the basin—NH3 emission amounts account for 2.5, 11.1, and 27.7 t/y/km2, mainly due to agriculture and livestock activities (∼97%). To study NH3 temporal and spatial variability, the Environmental Protection Agency of Lombardy Region has been monitoring NH3 concentrations across its territory since 2007, with 10 active monitoring sites. Annual and seasonal cycles are presented, along with a focus on different stations, including urban, low-mountain background, high-impact livestock, and rural background, highlighting the impact of various sources. Measurements indicate that within the Po basin, NH3 concentrations can reach up to 700 µg/m3 (as an hourly average) in proximity to the main gaseous NH3 source. Instrument intercomparisons among online monitors and passive vials, as well as different online monitors, are presented. Therefore, this paper provides crucial data to understand the formation of secondary inorganic aerosols in one of the most important hotspot sites for air pollution.

Evaluation and health risk assessment of phthalates in Okpa (cow pea pudding) packaged and cooked with polyethene bags in Nsukka, Enugu state, South-East Nigeria

Environmental toxicants enter the body via ingestion, inhalation or dermal absorption. Food is one of the major ways by which these toxicants get into the body. Food packaging has evolved in so many ways that materials made with plastics and its additives (Phthalates) are now used. Phthalates are compounds used to make plastics to enhance its functionality. Some have been associated with some health hazards such as endocrine dysfunction, reproductive problems, skin irritations and cancer. The current study was performed to evaluate the risk associated with consuming phthalates in okpa (cow pea pudding). The phthalate quantification and health risks were evaluated using gas chromatography mass-spectrometry (GC–MS) and models adopted by environmental protection agency (EPA) respectively. The Phthalate identified in okpa were diethyl phthalate (DEP), di-n-Butyl phthalate (DBP), benzylbutyl phthalate (BBP), di-iso-butyl phthalate (DiBP), and di (2-ethylhexyl)phthalate DEHP. The total concentration of phthalate detected was 0.0653 mg/kg with DEP as the highest (0.0196 ± 0.000 mg/kg) and BBP as the least (0.0077 ± 0.001 mg.kg). The highest THQ evaluated was DiBP for both adults (2.84E−1) and children (1.42E−1). The THI for adults and children was 3.35E−1 and 3.01E−1 respectively. The THQ and THI values obtained for adults and children were all less than 1 implying that it is safe. The carcinogenic risk (CR) evaluated for adults and children were 7.23E−6 and 3.61E−5. These values obtained for the THQ, THI and CR all together were within the safe limits stipulated by USEPA, FAO and WHO. However, it is still pertinent to continuously monitor the level of phthalates that may migrate into okpa because red oil content variations may positively impact on its leaching ability.