Chemical Risk Research Articles

Identification and hazard prioritization of hydrophobic organic chemicals in flowback and produced water particles: Implications for water management

Hydraulic fracturing flowback and produced water (HF-FPW) has raised significant concerns owing to its potential impact on aquatic organisms and human health. Understanding the chemical composition of HF-FPW is crucial for developing appropriate management and remediation strategies. Herein, we performed nontarget screening of hydrophobic organic chemicals in the particulate phase of FPW (P-FPW) using gas chromatography-Orbitrap mass spectrometry coupled with cheminformatic analysis. In total, 5807 features were discovered, with 209 annotated with positive confidence levels, which were further classified based on their chemical taxonomy and functional use information. We found that benzenoids dominated the chemical class, followed by hydrocarbons. The annotated chemicals were classified into fragrances, catalysts, antimicrobials, antioxidants, and other classes. Chemical overlap across countries (China vs. Canada) and wells was observed, with most chemicals reaching peak intensity within 24 or 48 h after the initial flowback and gradually decreasing. Approximately two-thirds of the identified or annotated chemicals have not been previously reported or included in existing HF-related databases, indicating expanded chemical coverage by the current screening workflow. A Toxicological Priority Index (ToxPi) scheme, which integrates chemical properties, ecological toxicities, and in vivo exposure potentials, was adopted to prioritize chemicals for further evaluation. Seven chemicals were proposed as prioritized compounds, of which the ester derivative of perfluorobutanoic acid, octacosyl heptafluorobutyrate (confidence level 2), exhibited the highest ToxPi score. Notably, most prioritized substances have limited toxicological data and are beyond the routine monitoring of the HF industry, highlighting significant gaps in our understanding of HF-related chemical content and environmental risk associated with water management.

In vitro pharmacologic profiling aids systemic toxicity assessment of chemicals

An adapted in vitro pharmacology profiling panel (APPP) was developed that included targets used in the pharmaceutical industry alongside additional targets whose cellular functions have been linked to systemic toxicities. This panel of 83 target assays was used to profile the activities of 129 cosmetic relevant chemicals with diverse chemical structures, physiochemical properties and cosmetic use types. Internal data consistency was proved robust, as evidenced by the reproducibility between single concentration and concentration-response data and showed good concordance with data reported in the ToxCast and drug excipient datasets. We discuss how the data can be analyzed and multiple potential contexts of use illustrated by case studies, alongside other new approach methodologies, to support cosmetic chemical risk assessments that do not require data from new animal studies.

Directly measuring octanol-air partition ratios using a gas chromatography retention time (GC-RT) method

The octanol-air partition ratio (KOA) is a fundamental property used for screening chemicals for concern, depending on their potential to bioaccumulate and harm living systems. With millions of chemicals used in commerce, unfortunately, less than 800 compounds currently have experimentally measured KOA values due to limitations in traditional measurement techniques. We aimed to develop a direct gas chromatography retention time (GC-RT) method using a custom-packed column, with octanol as the stationary phase, for rapidly measuring KOA. We installed the column into a GC-mass spectrometry system and isothermally measured retention times of 15 volatile organic compounds. We calculated KOA values at experimental temperatures from the retention times and extrapolated the results to values at 25 °C using the Van't Hoff equation. Our directly measured log KOA values at 25 °C spanned 3.66 log units (0.820–4.48). Except for alcohols, our measured values agree with literature log KOA values (root mean square error, RMSE = 0.50). The discrepancy probably arose from differences in how well our method versus the literature methods capture measurement artifacts, specifically, gas-phase adsorption to the octanol phase and hydrogen bonding interactions. This proof-of-concept study demonstrates that our direct GC-RT method is promising for rapidly measuring KOA to support chemical risk assessment.

Application of STPA for Comprehensive Risk Analysis of Naphtha Explosion Hazards

Chemical accidents always result in significant losses due to the flammable, explosive, and toxic characteristics of hazardous chemicals. Analysis of process safety parameters is an effective way to prevent hazardous chemical accidents and reduce losses. System-theoretic process analysis (STPA) is a newer hazard analysis technique that is based on systems theory. It has been shown to be effective in identifying hazards in other industries, but its application in oil and gas plants is still rare and limited due to systems complexities and other challenges. This paper aims to apply the STPA method to a complex system “column C-63” at the Skikda RA1K refinery to prevent the explosion scenario of naphtha. The results show that STPA was able to identify the root causes of the explosion scenario, which is important for preventing chemical risks.

Batch and column studies for the removal of basic red-46 dye and textile by using magnesium oxide (MgO), strontium titanium trioxide (SrTiO3), cobalt- and iron-doped lanthanum chromium trioxide (Co.Fe.LaCrO3), and cadmium sulfide (CdS)-doped graphene oxide nanocomposites.

Despite efforts to reduce the risk of toxic chemicals, colors, and dyes being released into the environment from urban and industrial areas, there is still cause for concern. Colored water must be filtered and sterilized before it can be used for irrigation. The utilization of metal oxide and nanocomposite materials in wastewater treatment procedures appears to be a viable option for the future. Therefore, different compounds were doped with graphene oxide to identify the best material for dye removal by the adsorption process. According to recent studies, the ideal conditions for graphene oxide-doped magnesium oxide (GO/MgO) are as follows: pH 10 showed the highest adsorption capacity (qe) at 49.4mg/g; an adsorbent dosage of 0.01g/50mL showed 48.3mg/g qe; a shaking time of 30min resulted in 44.2mg/g qe; an initial dye concentration of 100mg/L yielded 53.6mg/g qe; and a temperature of 35°C gave 49.5mg/g qe. For graphene oxide-doped strontium titanate (GO/SrTiO3), the optimum conditions were as follows: pH 10 with 45.8mg/g qe; an adsorbent dose of 0.01g/50mL with 40.5mg/g qe; a shaking time of 30min with 75mg/g qe; and a temperature of 35°C with 44.7mg/g qe. Graphene oxide-doped cobalt and iron-doped lanthanum chromium titanate (GO/Co.Fe.LaCrO3) showed optimum conditions of pH 9 with 34.2mg/g qe; an adsorbent dose of 0.01g/50mL with 27.5mg/g qe; a shaking time of 45min with 33.2mg/g qe; an initial dye concentration of 100mg/L with 37.6mg/g qe; and a temperature of 35°C with 42.5mg/g qe. Graphene oxide-doped cadmium sulfide (GO/CdS) showed the following optimum conditions: pH 8 with 23.1mg/g qe; an adsorbent dose of 0.01g/50mL with 25.5mg/g qe; an initial dye concentration of 75mg/L with 28.3mg/g qe; and a temperature of 35°C with 33.5mg/g qe. The pseudo-first-order model was the best fit only for graphene oxide-doped magnesium oxide (GO/MgO) with an R2 value of 0.966, while the pseudo-second-order adsorption isotherm was the best fit for all four products, with R2 values ranging from 0.991 to 0.998. Additionally, the Langmuir adsorption isotherms provided good results for all four products, with R2 values ranging from 0.957 to 0.985. The Freundlich adsorption kinetics showed satisfactory fit only for graphene oxide-doped magnesium oxide (GO/MgO) and graphene oxide-doped cadmium sulfide (GO/CdS), with R2 values of 0.951 and 0.982, respectively. To examine the characteristics and practicality of the adsorption process, certain thermodynamic variables were calculated. The adsorption capability of the most efficient nanocomposites for the degradation of basic red-46 was significantly affected by various concentrations of heavy metal ions and electrolytes. In dye solutions containing surfactants/detergents, the adsorption efficiency of several effective photocatalysts for basic dyes was significantly reduced. A 0.5M HCl solution was found to be the most effective for desorption. In column investigations, the optimal bed height, flow velocity, and dye intake levels were determined to be 3cm, 1.8mL/min, and 70mg/L, respectively, for maximal adsorption of basic red-46. The adsorption investigation of genuine textile waste products has also been carried out to facilitate the practical deployment of this approach. The methods used in this study were cost-effective, easy to handle, and eco-friendly and involved no hazardous materials in the synthesis, making the resulting materials non-hazardous. All these methods were part of green chemistry.

Safety and sustainability by design: An explorative survey on concepts’ knowledge and application

The Safe and Sustainable by Design (SSbD) concept integrates safety and sustainability of chemicals and materials, throughout their entire life cycle and minimizes their environmental footprint. The European Commission (EC) in 2022 developed a framework to practically apply SSbD. This study investigated the knowledge on SSbD and the operationalization of such framework among the partners of the Partnership for the Assessment of Risks from Chemicals (PARC) program. Forty-one responses from 32 PARC Institutions were collected through a 21 item-online survey. Seventy-three % of the respondents had knowledge of SSbD, although only 49 % reported to have been directly engaged into SSbD projects. The EC-SSbD framework was applied by the 26 % of participants and in 47 % of cases it included a (re)design phase. With respect to the safety and sustainability, the assessment of the hazard, the human health and safety aspects in the production and processing, and the human health and environmental aspects in the final application of the chemical/material was addressed by the 74 %, 52 % and 65 % of the respondents. Lower percentages of positive responses regarded the environmental, social and economic sustainability assessment: 35 %, 20 % and 13 %, respectively. Overall, while the framework provided the necessary building blocks and opportunities for SSbD, concerted and iterative Research, Industry, and Academia efforts are necessary to develop/improve assessment methods, models and tools to make SSbD as an approach to chemical risk assessment and management to protect human health and the environment, and ensure to operate within the planetary boundaries.

Assessment of Uranium Pollution in Ground Water and Human Health in Balod District, Chhattisgarh

A laser fluorimetric technique was used to measure the amount of uranium present in samples of groundwater from the Balod district, Chhattisgarh, central India. For this purpose, we collected twenty-nine water samples from different villages in the Balod district, Chhattisgarh from September 2022 to June 2023. Here, the concentration of uranium in the sample of water ranges from 0.10 to 66.7(µg/l). A maximum number of samples had uranium contamination levels below the acceptable limit (30 µg/l), except for Siwani village (66.7µg/l), as approved by the WHO. The USEPA recommendations were used to determine the chemical risk ( Non-carcinogenic) and excess lifetime carcinogenic risk (ECR) caused by groundwater consumption. The allowed excess lifetime cancer risk ( ELCR) value of 1.0´10-4was found to be exceeded in a few water samples by the risk of cancer resulting from drinking water. The LADD value of 18 % and HQ value of 24% of the water sample exceed the permissible limit indicating a high risk of chemical poisoning. In this analysis, we found that the area's uranium's chemical toxicity may be the cause of non-carcinogenic health problems, but eventually, there is no Carcinogenic (radiological) risk to people.

Development of a comprehensive open access "molecules with androgenic activity resource (MAAR)" to facilitate risk assessment of chemicals.

The increasing prevalence of endocrine-disrupting chemicals (EDCs) and their potential adverse effects on human health underscore the necessity for robust tools to assess and manage associated risks. The androgen receptor (AR) is a critical component of the endocrine system, playing a pivotal role in mediating the biological effects of androgens, which are male sex hormones. Exposure to androgen-disrupting chemicals during critical periods of development, such as fetal development or puberty, may result in adverse effects on reproductive health, including altered sexual differentiation, impaired fertility, and an increased risk of reproductive disorders. Therefore, androgenic activity data is critical for chemical risk assessment. A large amount of androgenic data has been generated using various experimental protocols. Moreover, the data are reported in different formats and in diverse sources. To facilitate utilization of androgenic activity data in chemical risk assessment, the Molecules with Androgenic Activity Resource (MAAR) was developed. MAAR is the first open-access platform designed to streamline and enhance the risk assessment of chemicals with androgenic activity. MAAR's development involved the integration of diverse data sources, including data from public databases and mining literature, to establish a reliable and versatile repository. The platform employs a user-friendly interface, enabling efficient navigation and extraction of pertinent information. MAAR is poised to advance chemical risk assessment by offering unprecedented access to information crucial for evaluating the androgenic potential of a wide array of chemicals. The open-access nature of MAAR promotes transparency and collaboration, fostering a collective effort to address the challenges posed by androgenic EDCs.

What's in the Blood? Temporalities at Play in Diet-Related Risk Management Testing Practices

In this paper, I look at two different sets of practices that are part of the risk management apparatus in place in Québec & Canada to apprehend and control risks associated with food consumption. More specifically, I contrast diabetes and chemical contaminants risk management testing practices, so as to compare how both frame and approach risks, in a context where recent research in social sciences, epigenetics and environmental sciences increasingly points to “environmental” pathways of disease causation while many chronic conditions remain highly individualized in public and health discourses. The analysis pays close attention to the different temporalities discursively created, considered, and neglected in these practices in order to understand how risk is approached and worked on. This highlights the power relations that inform how we care (or not) for (certain) bodies, inflecting in particular ways their—uneven—becomings. I argue that the Canadian biotechnological apparatus of testing practices meant to apprehend and control diet-related risks contributes to foreclosing the temporalities of health and illness considered and acted upon. As such, the apparatus contributes to (re)producing inequalities, here mostly health related ones, as well as creating differentiated biological materialities.

Determination of Trace Elements Content of a Popular Traditional Herbal Medicine Used for Internal Hemorrhoids Treatment in Katsina State, Nigeria

Study’s Excerpt/Novelty Assessment of toxic metal concentrations of a widely used traditional herb in Katsina state, was carried out. Flame atomic absorption spectrophotometry and descriptive statistical analysis was employed in the research. Pb, Cr, and As were found to be beyond WHO/FAO thresholds. Full Abstract There has been an increase in the utilization of traditional herbal drugs for different medications and health care in Katsina state. This is possibly due to the growing need for complementary disease treatment, relative cheapness, availability, and wider distribution. Raw samples of a popularly used traditional herb (locally named - Dan Lambar Rimi) were purchased from local markets, prepared, and analyzed using a flame atomic absorption spectrophotometer for Pb, Cr, As, Co, Ni, and Cd concentrations. The obtained concentrations were then summarized using descriptive statistics in SPSS Version 27. The results for the elements analyzed were Ni (0.83 ± 0.15), Cd (0.20 ± 0.01), Pb (21.5 ± 6.63), As (2.10 ± 0.70), Cr (2.36 ± 0.37), and Co (1.15 ± 0.22) ppm. Cr, Pb and As concentrations were greater than the WHO/FAO threshold limits for herbal medicines, while that of Cd was within the recommended threshold. Furthermore, the concentrations of these metals (As, Cr, and Pb) were greater than the WHO/FAO acceptable threshold in 50% of the herbal samples analyzed. Therefore, these metals can pose a threat to public health, especially considering the conventional way in which this herbal medicine is used. With deliberate improvement in hygiene during its preparation prior to consumption, the risk will be brought to a minimal. Future studies should perform a detailed chemical risk assessment, especially when we look at the increase in the number of diseases of unknown etiology in the region.

Adolescent exposure to tris(1,3-dichloro-2-propyl) phosphate (TCPP) induces reproductive toxicity in zebrafish through hypothalamic-pituitary-gonadal axis disruption

Tris(1,3-dichloro-2-propyl) phosphate (TCPP), a prevalent organophosphorus flame retardant in aquatic environments, has raised significant concerns regarding its ecological risks. This study aims to explore the impacts of TCPP on the reproductive functions of zebrafish and delineate its gender-related toxic mechanisms. By assessing the effects on zebrafish of 10 mg/L TCPP exposure from 30 to 120 days post-fertilization (dpf), we thoroughly evaluated the reproductive capability and endocrine system alterations. Our findings indicated that TCPP exposure disrupted gender differentiation in zebrafish and markedly impaired their reproductive capacity, resulting in decreased egg laying and offspring development quality. Histological analyses of gonadal tissues showed an abnormal increase in immature oocytes in females and a reduction in mature sperm count and spermatogonial structure integrity in males, collectively leading to compromised embryo quality. Additionally, molecular docking results indicated that TCPP showed a strong affinity for estrogen receptors, and TCPP-treated zebrafish exhibited imbalanced sex hormones and increased estrogen receptor expression. Alterations in genes associated with the hypothalamic-pituitary-gonadal (HPG) axis and activation of the steroidogenesis pathway suggested that TCPP targets the HPG axis to regulate sex hormone homeostasis. Tamoxifen (TAM), as a competitive inhibitor of estrogen, exhibited a biphasic effect, as evidenced by the counteraction of TCPP-induced effects in both male and female zebrafish after TAM addition. Overall, our study underscored the gender-dependent reproductive toxicity of TCPP exposure in zebrafish, characterized by diminished reproductive capacity and hormonal disturbances, likely due to interference in the HPG axis and steroidogenesis pathways. These findings emphasize the critical need to consider gender differences in chemical risk assessments for ecosystems and highlight the importance of understanding the mechanisms underlying the effects of chemical pollutants on the reproductive health of aquatic species.

Modeling the Toxicokinetics of Suspensions of Soluble Metallic Nanomaterials.

Proper risk assessment of the many new nanoforms (NFs) that are currently being developed and marketed is hindered by constraints in time and resources for testing their fate and (eco) toxicity profile. This problem has also been encountered in conventional chemical risk assessments, where the definition of related chemical groups can facilitate risk assessment for all class members. Whereas grouping and read-across methods are well established, such approaches are in the early stages of development for NFs. In this study, a modeling framework was developed for grouping NFs into distinct classes regarding the contribution of released ions to suspension-induced toxicity. The framework is based on combining dissolution rate constants of NFs with information about the toxicokinetics of the NFs and the dissolution products formed. The framework is exemplified for the specific case of suspension toxicity of metallic NFs (silver and copper). To this end, principles of mixture toxicity and dose-response modeling are integrated to derive threshold values for the key NF properties determining suspension toxicity: size, shape, and chemical composition. The threshold values thus derived offer a possible solution for the high-throughput screening of NFs according to their morphological and compositional properties in a regulatory context.

Food for thought — Paving the way for a UK roadmap towards optimum consumer safety: Development, Endorsement and Regulatory acceptance of New Approach Methodologies (NAMs) in Chemical Risk Assessment and Beyond

Advances in biosciences, chemistry, technology, and computer sciences have resulted in the unparalleled development of candidate New Approach Methodologies over the last few years. Many of these are potentially invaluable in the safety assessment of chemicals, but very few have been adopted for regulatory decision making. There is an immediate opportunity to use NAMs in safety assessment where the vision is to be able to predict risk more rapidly, accurately, and efficiently to further assure consumer safety.In order to achieve this, the UK Food Standards Agency (FSA) and the Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (COT) have developed a roadmap towards acceptance and integration of these new approach methodologies into safety and risk assessments for regulatory decision making. The roadmap provides a UK blueprint for the transition of NAMs from the research laboratory to their use in regulatory decision making. This will require close collaboration across disciplines (chemists, toxicologists, informaticians, risk assessors and others), and across chemical sectors, to develop, verify and utilise appropriate models. Linking up internationally, and harmonization will be fundamental.

Particulate matter in necropsy activities: experience from a health operators’ exposure monitoring campaign

BackgroundOperators in the obituary and necropsy sectors are exposed to various environmental hazards during specific tasks. Despite this exposure, occupational risks have often been underestimated, resulting in a lack of substantial evidence. The primary objectives of this study were to identify sources of chemical risk, establish procedures for monitoring and quantifying exposure during necropsy activities, and recommend adjustments to regulatory guidelines to protect the health of the operators. The study was conducted at the Legal Medicine Unit of the Umberto I General Hospital in Rome, focusing on the quantitative measurement of particulate matter (PM) exposure among at-risk operators during necropsy activities. Environmental levels of total suspended particles, PM10, PM4, PM2.5, and PM1 were assessed by evaluating the average, minimum, and maximum instantaneous indoor concentrations using an airborne analyzer.ResultsThe monitoring activities revealed that the PM concentrations were significantly lower than the recognized reference values. However, bone sawing, body removal, and cleaning were identified as high-risk maneuvers for dust suspension.ConclusionsOur study highlighted specific risks associated with necropsy activities, particularly concerning timing and certain maneuvers. These results may lead to interventions for improving current prevention procedures, implementing good practices, and developing specific guidelines to enhance operator safety.

Evaluation of selected crops for rearing predatory mite (Phytoseiulus persimilis), a predator of two-spotted red spider mites

The damage caused by two-spotted spider mites, and the risks associated with chemical pesticides, including health and environmental risks necessitate the exploration of sustainable pest management methods. Predatory mites, such as Phytoseiulus persimilis, are effective biocontrol agents against pests like the two-spotted spider mite (Tetranychus urticae). Thus, this study aimed to evaluate the suitability of different crops for rearing predatory mites (Phytoseiulus persimilis) and assess their effectiveness in controlling two-spotted spider mites (Tetranychus urticae). Linear regression analysis showed significant effects of selected crops on mite populations across all collection times (Collection 1: F (3, 8) = 22.46, p = 0.0003; Collection 2: F (3, 8) = 11.45, p = 0.0029; and Collection 3: F (3, 8) = 9.17, p = 0.0057). ANOVA showed significant differences in mite counts among the crops (F (3, 32) = 18.06, p < 0.001), corroborated by bootstrapping analysis. Beans demonstrated the highest potential for supporting predatory mite populations, followed by eggplant and black nightshade, illustrating that crop diversification can enhance predatory mite production while suggesting adoption of Integrated pest management (IPM) strategies to reduce pesticide costs and environmental impacts. There is the need for collaborative research and policy support to drive innovation and promote sustainable pest management practices in agriculture, thus addressing pesticide-use related environmental issues.

CEC02-04 The virtual human approach to animal-free chemical hazard and risk assessment in developmental toxicology

CEC02-04 The virtual human approach to animal-free chemical hazard and risk assessment in developmental toxicology

P19-93 Using high throughput screening asapreliminary tool for predicting environmental risk of chemicals

P19-93 Using high throughput screening asapreliminary tool for predicting environmental risk of chemicals

P19-85 Alternative approaches to chemical risk assessment: challenging the current animal-based threshold approach

P19-85 Alternative approaches to chemical risk assessment: challenging the current animal-based threshold approach

P19-66 Industrial case studies in product design and chemical risk assessment

P19-66 Industrial case studies in product design and chemical risk assessment

S28-02 AI in chemical risk assessment: opportunities, challenges, solutions

S28-02 AI in chemical risk assessment: opportunities, challenges, solutions