Potential Exposure Pathways Research Articles

Human exposure to microplastics: A review on exposure routes and public health impacts

The presence of microplastics (MPs) in human body parts has raised significant concerns due to their status as a major environmental pollutant. Despite existing methods for detecting and identifying MPs in human tissues, there is a lack of standardized techniques, compromising the comparability of data across studies. This review critically analyzes the current knowledge on MPs in human body parts, sources and potential exposure pathways. This study underscores the urgent need for standardized and validated techniques for accurate MP analysis and characterization in human tissues, addressing the methodological challenges in MP detection. The findings of this review indicate that humans are exposed to MPs potentially through several routes such as ingestion, inhalation and dermal contact. However, the exact routes for MPs entering the body remain unclear. It also examines the wide range of health impacts associated with MPs, such as oxidative stress, inflammatory responses, endocrine disruption, and potential genotoxicity. Nevertheless, the cellular and molecular mechanisms underlying these effects are still not well understood, especially when considering the diverse concentrations, shapes, and sizes of MPs. Therefore, further research is essential, particularly to enhance epidemiological studies that can robustly establish the link between MP exposure and health impacts in large populations. Advancing this knowledge will be crucial for developing effective strategies to safeguard both environmental and public health from the detrimental effects of MPs.

Characterization and potential toxicity of asbestiform erionite from Gawler Downs, New Zealand

Abstract Erionite is the name for a zeolite mineral series originating from diagenesis or hydrothermal alteration of volcanic rocks. The particular erionite “species” is based on the dominant extra-framework cation, erionite-Ca, erionite-K, or erionite Na. Irrespective of the species, erionite can display a fibrous/asbestiform morphology and has been linked with cases of malignant mesothelioma, a disease typically associated with asbestos exposure. Characterization of new discoveries of erionite is therefore important to assess any potential exposure hazards. This study describes a new asbestiform erionite from vesicles within the Upper Cretaceous Mt. Somers Volcanics Group (MSVG), Canterbury, New Zealand. The erionite is within the Hinds River Dacite, the youngest unit within the MSVG at Gawler Downs, ~100 km west of Christchurch, in the foothills of the Southern Alps. A multi-analytical approach was taken to analyze the sample which included micro-Raman spectroscopy, thermogravimetric analysis, electron microscopy, electron microprobe analysis, and X-ray powder diffraction with the Rietveld method. Results confirmed the mineral as fibrous erionite-K. The chemical composition of the mineral is unique due to the presence of higher levels of Mg. While Fe was also identified, this was due to smectite flakes occurring on the surface of the erionite fibers. According to the World Health Organization (WHO) respirable mineral fiber definition, where length ≥5 μm, width ≤3 μm, and aspect ratio (L/w) ≥3:1, the Gawler Downs erionite fibers are respirable, while the fibers themselves exceed respirable thickness. In addition to morphology, a value for the potential toxicity model was computed to be 2.28 for the Gawler Downs erionite. This is similar to those of other carcinogenic erionites from Karain, Turkey (2.33), and Nevada, U.S.A. (2.28). Taken together, results indicate Gawler Downs erionite represents an environmental hazard. Nevertheless, further investigation is required to determine potential environmental exposure pathways by which erionite may become airborne and assess the actual environmental risk in the Gawler Downs area.

Per- and polyfluoroalkyl substances (PFAS) in Indian environment: Prevalence, impacts and solutions

Per- and polyfluoroalkyl substances (PFAS) pose a significant and growing environmental challenge worldwide due to their remarkable persistence, widespread presence, and potential to adversely affect human health. This review offers a holistic investigation of current knowledge regarding PFAS in India. Existing research demonstrates the presence of PFAS in various environmental compartments, including water bodies, soil/sediment, atmosphere, and even wildlife. Furthermore, the review explores the potential ecological and human exposure pathways. Some of these pathways include consumption of contaminated drinking water, PFAS-laden food, and inhalation of dust particles containing PFAS. The potential health impacts on humans and biota are then elaborated, highlighting developmental problems, endocrine disruption, and even an increased risk of certain cancers. The findings strongly suggest that industrial activity, urbanization, and consumer product usage are significant contributors to environmental PFAS contamination. A critical gap identified within this review is the absence of established regulations for PFAS usage and disposal within the Indian environment. The review summarizes existing remediation techniques, providing a comprehensive strategy for managing PFAS in the Indian context. The implementation of stringent regulations governing PFAS production, use, and environmental discharge, coupled with the exploration of non-fluorinated alternatives, is imperative. Additionally, the deployment of advanced water treatment technologies specifically designed for PFAS removal and the fostering of collaborative research and development efforts are crucial steps towards mitigating PFAS contamination. In conclusion, this review emphasizes the urgent need for a multifaceted approach to manage PFAS in India.

PFAS emissions from functional textiles using micro-chamber and thermal desorption coupled to two-dimensional gas chromatography-time of flight mass spectrometry (TD-GC×GC-TOF MS)

Per- and polyfluoroalkyl substances (PFAS), in the polymeric form, have been used extensively in functional textiles, including firefighter's turnout gear (e.g., jackets and pants), where PFAS are applied to confer oil and water resistance. However, growing concerns over the persistence, potential toxicity, and environmental impact of PFAS have prompted a thorough assessment of potential exposure pathways. Here, we report the emission of PFAS from three firefighter turnout gear jackets at 38 °C. Volatile emissions from the three layers (outer layer, moisture barrier, and thermal liner) were collected onto sorbent tubes via dynamic headspace sampling using a micro-scale chamber device kept at 38 °C for one hour. The emission was characterized using thermal desorption (TD) coupled to two-dimensional gas chromatography - time-of-flight mass spectrometry (GC×GC–TOF MS). The enhanced separation capacity of GC×GC was essential due to the high number of compounds present in each sample, especially for the fabrics from used turnout gear jackets. Based on the filtering expressions, including two-dimensional retention time (1tr and 2tr) and PFAS diagnostic fragment ions (m/z 69, 95, and 131), fluorotelomer alcohols (FTOHs) and fluorotelomer acrylates were identified using standards and spectral matching with the NIST database. After conducting a non-targeted tile-based workflow, jackets (both used and unused) and layers were compared, resulting in the identification of the top 15 discriminating features from over 400 chromatographic peaks. Finally, preliminary FTOH emission experiments showed some usage and layers trends that are aligned with those reported using solvent extraction. Highest levels of FTOHs were found in the moisture barrier, followed by the outer layer and the thermal liner. Older jackets emitted higher levels of 8:2 FTOH and 10:2 FTOH than a newer jacket. In contrast, a newer jacket used for one year had emissions containing higher levels of 6:2 FTOH. Investigating routes of exposure and identifying new PFAS targets are critical steps in evaluating the environmental and health impacts of these persistent chemicals.

Discarded vehicle tires and their association with mosquito vector abundance across socioenvironmental gradients in New Orleans, LA.

Discarded vehicle tires serve as habitat for mosquito vectors. In New Orleans, Louisiana, discarded tires are an increasingly important public concern, especially considering that the city is home to many medically important mosquito species. Discarded tires are known to be associated with mosquito abundance, but how their presence interacts with other socioenvironmental gradients to influence mosquito ecology is poorly understood. Here, we ask whether discarded tire distribution could be explained by social factors, particularly median income, home vacancy and human population density, and whether these factors interact with urban heat islands (UHI) to drive mosquito vector assemblages. We surveyed tire piles across the city and adult mosquitoes in 12 sites, between May and October of 2020. We compared this data with the social indicators selected and UHI estimates. Our results show that median income and human population density were inversely related to tire abundance. Tire abundance was positively associated with Aedes albopictus abundance in places of low heat (LS) severity. Heat was the only predictor for the other monitored species, where high heat corresponded to higher abundance of Aedes aegypti, and LS to higher abundance of Culex quinquefasciatus. Our results suggest that low-income, sparsely populated neighborhoods of New Orleans may be hotspots for discarded vehicle tires, and are associated with higher abundances of at least one medically important mosquito (Ae. albopictus). These findings suggest potential locations for prioritizing source reduction efforts to control mosquito vectors and highlight discarded tires as a potential exposure pathway to unequal disease risk for low-income residents.

Key environmental exposure pathways to antimicrobial resistant bacteria in southern Malawi: A SaniPath approach

Antimicrobial resistance (AMR) poses a severe global health threat, yet the transmission pathways of AMR within communal public environments, where humans and animals interact, remain poorly explored. This study investigated AMR risk pathways, prevalence, and seasonality of extended-spectrum β-lactamase (ESBL) producing E. coli and K. pneumoniae, and observed practices contributing to environmental contamination within urban, peri-urban, and rural Malawi.Using the SaniPath tool, in August 2020, transect walks across three Malawian study sites identified potential AMR exposure pathways, including drains, standing water, soil, and areas of communal hand contact. Subsequently, from September-2020 to August-2021, 1440 environmental samples were collected at critical points along exposure routes (n = 40/month from each site). These underwent microbiological analysis using chromogenic agar techniques to detect the presence of ESBL E. coli and ESBL K. pneumoniae.Results showed the highest ESBL prevalence in urban environments (68.1 %, 95%CI = 0.64–0.72, p < 0.001) with a higher ESBL presence seen in drains (58.8 %, 95%CI = 055–0.62, p < 0.001) and soil (54.1 %, 95%CI = 0.46–0.62, p < 0.001) compared to other pathways. Environmental contamination was attributed to unavailability and poor condition of sanitation and hygiene infrastructure based on key informant interviews with community leaders (n = 9) and confirmed by independent observation. ESBL prevalence varied between seasons (χ2 (2,N = 1440) = 10.89, p = 0.004), with the highest in the hot-dry period (55.8 % (n = 201)). Prevalence also increased with increased rainfall (for ESBL E.coli).We highlight that community environments are likely to be a crucial component in AMR transmission, evident in the abundance of ESBL bacteria in identified exposure pathways. Additionally, poor sanitation infrastructure and practices coupled with seasonal dynamics further affect the presence of ESBLs in communal environments. Therefore, a context appropriate whole system approach that tackles infrastructure and behavioural factors, supported by effective surveillance is required to impact AMR and a range of aligned development challenges in these settings.

Microparticles of arsenic water treatment media and water softener resin observed in treated water at private wells.

Observation of arsenic water treatment adsorption media in the treated water of several homes with high arsenic private wells led to the hypothesis that treatment media was escaping the treatment systems and entering the plumbing and drinking water. Our research at 62 homes identified that microparticles of arsenic water treatment media and/or water softener resin had escaped the treatment system in 71% of the homes. This is a potential health hazard as ingesting arsenic treatment media or water softener resin may lead to an elevated ingestion exposure to arsenic and other contaminants. Potential causes of media escape from the treatment systems include media observed to be smaller in size than specifications and media breaking into smaller pieces. One interim solution to media escape is installation of a post-treatment sediment filter. New developments in media durability or treatment system design and maintenance may be needed to prevent media escaping into drinking water. PRACTITIONER POINTS: Arsenic in private wells is often treated with point-of-entry whole house adsorption systems. Arsenic adsorption treatment media and/or water softener resin was observed in treated water at 44 of 62 homes inspected. Water treatment media escaping into treated water is a potential hazardous exposure pathway. Potential causes and solutions are discussed.

Can Bees Detect Perfluorooctane Sulfonate (PFOS)?

The European honey bee (Apis mellifera) is an important crop pollinator threatened by multiple stressors, including exposure to contaminants. Perfluorooctane sulfonate (PFOS) is a persistent global contaminant that accumulates and biomagnifies in food chains and is detected in honey. Even sublethal exposure to PFOS is detrimental to bee health, but exposure routes are unclear and nothing is known about bee response (detection, avoidance, or attraction) to PFOS. Using Y-mazes, we studied the response of individual bees to PFOS-spiked sugar syrup at four concentrations, 0.02, 30, 61 and 103 µg L-1. Bee activity, choice behavior, and drink duration for unspiked and spiked sugar syrup was recorded for 10 min in the Y-maze system. Most bees (≥80%) tasted and then drank the sugar syrup solutions, including the PFOS-contaminated syrup. Only at 61 and 103 µg L-1 did bees significantly avoid drinking PFOS-spiked syrup, and only when given a choice with unspiked syrup. When the choice of consuming unspiked syrup was removed, the bees drank PFOS-spiked syrup at all the PFOS concentrations tested, and avoidance was not evident. Avoidance was not observed in any treatment at 0.02 or 30 µg L-1 PFOS, concentrations that are frequently reported in environmental waters in contaminated areas. These findings confirm that bees will access PFOS-contaminated resources at concentrations detrimental to the colony health, and provide evidence of potential exposure pathways that may threaten crop pollination services and also human health via food chain transfer in PFOS-contaminated areas. Environ Toxicol Chem 2024;43:1638-1647. © 2024 SETAC.

Variation of total alpha and beta activities and Rn-222 concentrations in the water supply system of an Italian volcanic region: How safe is tap water for human consumption?

Total alpha and beta activities and Rn-222 concentrations were determined in water from different sections of seven aqueducts belonging to the water supply system of Campania region (Italy), known worldwide for its volcanism. Statistical analysis was performed on data to account for their variability across the aqueduct sections, and results were discussed considering the geology of reservoirs, the potential mixing processes occurring along the pipe network, the building/constituting materials of the aqueduct sections, and the integrity of the infrastructure. Guidelines proposed by Italian and international regulation entities were considered to determine if total alpha and beta activities and Rn-222 concentrations found at the taps of the different aqueducts should be considered detrimental to public health. Based on a deterministic and a stochastic approach, a health risk assessment was also tested for Rn-222, assuming direct ingestion and showering as potential exposure pathways. Results showed that applying guidelines returned an absence of hazard, whereas risk assessment returned a high probability of exposure to unacceptable Rn-222 doses for some aqueducts. Beyond the usefulness of obtained results to plan actions to improve the safety of drinking water in Campania, our outcomes represent a warning for bodies dealing with public health at any level: the use of guidelines can bring an underestimation of the risks exerted by the exposure to Rn-222 on human health. Further, using a probabilistic approach in risk assessment accounting for uncertainty can favor risk forecasts based on more “realistic” scenarios.

Understanding the role of household hygiene practices and foodborne disease risks in child stunting: a UKRI GCRF Action Against Stunting Hub protocol paper

IntroductionEnvironmental hygiene and food safety are important determinants of child stunting. This research aims to explore the relationship between child stunting and household hygiene practices and behaviours, including the availability...

Mercury distribution, exposure and risk in Poyang Lake and vicinity, China

Mercury (Hg), especially methylmercury (MeHg), which is highly neurotoxic, is a global pollutant that can affect human health because of its accumulation in aquatic products. Poyang Lake, an inland lake in China, has been significantly affected by human activity, yet there is limited understanding of local mercury contamination and potential exposure pathways to humans. In this study, we explored the risks of mercury exposure by sampling sediments, plants, and aquatic organisms in the lake and surrounding areas and analyzing total Hg (THg) and MeHg levels. Sediment sampling was conducted at the main lake, rivers, rice paddies, and fishponds. Two dominant species of plants and 15 species of aquatic organisms were sampled and analyzed. We assessed the characteristics of mercury in sediments using the geo-accumulation index (Igeo), mercury exposure using the biomagnification factor (BMF) and biota sediment accumulation factor (BSAF), and risks using thresholds for adverse effects. The highest THg concentrations (137.04 ± 44.3 ng g−1 dw) were detected in the main lake sediments, whereas the highest MeHg concentrations (0.47 ± 0.6 ng g−1 dw) were detected in fishpond sediments. Mercury accumulation in the main lake sediments could be assessed as contaminated (Igeo > 0: 81.6%). Yellow catfish had the highest mercury concentration (THg 770.69 ± 199.7 ng g−1 dw; MeHg 741.93 ± 168.8 ng g−1 dw). Piscivores were adversely affected by carnivorous fish (50.8%), but all fish concentrations did not exceed the food safety standards recommend by China and the WHO. The mercury exposure results revealed significant Hg biomagnification and enrichment (BMF >1: 94.55%; BSAFmax = 1218). Long-term monitoring of aquatic organisms is warranted.

Environmental risk assessment of landfill

The paper aims to conduct a risk analysis approach that can be used to manage landfill impacts on the environment and public health. This study reviewed the application of environmental risk assessment in landfills. Assessment has been conducted for 30 articles from 2018-2022 resulting in the summary of the baseline data, hazard identification, exposure assessment, risk characterization, and risk management. The study found the necessity of detailed baseline data of landfill sites, identifying relevant toxicity data, recognizing exposed receptors, and potential exposure pathways. It is necessary to conduct research that considers the age of the landfill (old and new landfill) to find out the cumulative effects of the landfill and research related to the impact of the landfill on the health of communities around the landfill at a certain distance from the landfill.

Understanding the role of biomolecular coronas in human exposure to nanomaterials.

Nanomaterials (NMs) are increasingly used in medical treatments, electronics, and food additives. However, nanosafety-the possible adverse effects of NMs on human health-is an area of active research. This review provides an overview of the influence of biomolecular coronas on NM transformation following various exposure routes. We discuss potential exposure pathways, including inhalation and ingestion, describing the physiology of exposure routes and emphasising the relevance of coronas in these environments. Additionally, we review other routes to NM exposure, such as synovial fluid, blood (translocation and injection), dermal and ocular exposure, as well as the dose and medium impact on NM interactions. We emphasize the need for an in-depth characterisation of coronas in different biological media, highlighting the need and opportunity to study lung and gastric fluids to understand NM behaviour and potential toxicity. Future research aims to predict better in vivo outcomes and address the complexities of NM interactions with biological systems.

Mobility of crocidolite asbestos in sandy porous media mimicking aquifer systems

Asbestos is widely recognized as being a carcinogen when dispersed in air, but very little is known about its exposure pathways in water and its subsequent effects on human health. Several studies have proved asbestos presence in groundwater but failed to assess its mobility in aquifer systems. This paper aims to fill this gap by studying the transport of crocidolite, an amphibole asbestos, through sandy porous media mimicking different aquifer systems. To this purpose, two sets of column test were performed varying the crocidolite suspension concentration, the quartz sand grain size distribution, and the physicochemical water parameters (i.e., pH). The results proved that crocidolite is mobile in quartz sand due to the repulsive interactions between fibres and porous media. The concentration of fibres at the outlet of the column were found to decrease when decreasing the grain size distribution of the porous medium, with a bigger impact on highly concentrated suspensions. In particular, 5-to-10-µm-long fibres were able to flow through all the tested sands while fibres longer than 10 µm were mobile only through the coarser medium. These results confirm that groundwater migration should be considered a potential exposure pathway while implementing human health risk assessment.

Gender and zoonotic pathogen exposure pathways in a resource-limited community, Mpumalanga, South Africa: A qualitative analysis.

The Mnisi community is a livestock-dependent community neighboring the Great Limpopo Transfrontier Conservation Area in South Africa. Here, zoonotic pathogens contribute to as many as 77% of cases of acute febrile illness. Previous gender-disaggregated analysis in the community has shown that men and women have different risks of zoonotic illness, suggesting that exposure routes for zoonotic infections should be further explored to inform gender-sensitive risk mitigation strategies. Using a One Health approach and ethnographic methodology, we examined interactions between community residents, domestic animals, and the built and natural environment to investigate potential exposure pathways for zoonotic infections from a gendered perspective. We combined data from direct household observations and focus group discussions on previously identified gendered tasks such as domestic animal care, water collection, and food preparation, and how and by whom these tasks were performed. We noted gender differences for household tasks, animal care duties, and environmental exposure. Both men and women access grazing land but for different tasks (water collection-females, cattle grazing-males), and both men and women experience more time in the bush in recent years due to decreased water availability. From observations, it was noted that men wore covered protective work clothes (such as long trousers and closed-toe shoes) more commonly than women did; women did not often wear these for household duties including water collection in the bush. We recommend that these gender-typed roles serve as critical control points for zoonotic pathogen exposure. For example, tick-bite exposure prevention should be directed at both men and women based on their daily activities, but prevention in men should target exposure from cattle and prevention in women should focus on personal protective measures during water and firewood collection. These findings can contribute to a more detailed understanding of the role of human behavior and critical control points for zoonotic disease-a significant contributor to acute febrile illness in this rural, resource-limited setting.

Fate of Per- and Polyfluoroalkyl Substances in Postconsumer Products during Waste Management

Per- and polyfluoroalkyl substances (PFAS) have been widely used in consumer products, and some inevitably end up as municipal solid waste. Significant knowledge gaps associated with the fate and release of PFAS from postconsumer products in solid waste management processes exist that limit our current ability to develop appropriate end-of-life management strategies for PFAS. The objectives of this paper are to summarize the current knowledge associated with the fate and release of PFAS from postconsumer products from commonly used waste management processes (including landfilling, recycling, composting, and incineration) and to use that information to identify knowledge gaps and potential exposure pathways for humans and the environment. The current results indicate that landfills are major sinks of PFAS because most PFAS-containing consumer products are landfilled, and PFAS was extensively reported in landfill leachate. More information is needed regarding the total influx of PFAS into landfills as well as landfill gas emissions. Recycling and composting also present potential exposure pathways. The reprocessing of carpet and paper packaging was reported to cause direct exposure to onsite workers through PFAS volatilization and dust emissions. Recycling can cause the circularity of PFAS in the new product and subsequent release throughout its lifespan. Composted food packaging was found to contain PFAS and could cause contamination during the land application of compost. The incineration of waste provides near-complete destruction (∼99%) of PFAS. However, some low-temperature regions within the furnace may still result in products of incomplete combustion, such as short-chain perfluoroalkyl acids and other stable fluorinated compounds, which may be released in incinerator ash. More information is needed regarding the mechanisms of PFAS thermal destruction. Case studies of PFAS product categories indicated that carpet and cosmetics might contribute to the release of more soluble and volatile PFAS, such as perfluoroalkyl acids and fluorotelomer alcohols during landfilling in leachate and gas. The fate of specific PFAS during waste management aligns well with their physical/chemical properties, such as solubility and volatility.

Parasites in Imported Edible Fish and a Systematic Review of the Pathophysiology of Infection and the Potential Threat to Australian Native Aquatic Species

Previous research has shown that certain types of edible fish imported into Australia are infected with Euclinostomum/Isoparorchis digenetic trematodes. In the present study, imported Channa fish were examined for parasites which were then morphologically identified to the lowest taxonomic unit possible. Here we provide the first Australian report of Pallisentis sp. Van Cleave, 1928 (Prevalence (P) 35.9%) of family Quadrigyridae; Genarchopsis sp. Ozaki, 1925 (P. 16.5%), family Derogenidae and Senga sp. Dollfus, 1934 (P. 4.8%) in edible imported Channa fish (n = 103). Pallisentis sp. and Senga sp. have invasive hold fast organs which cause significant mechanical damage to fish intestinal structures and Euclinostomum/Isoparorchis cause severe pathology and loss of marketability in infected fish. These exotic parasites, if introduced into Australia, have the potential to negatively impact the health, fecundity, resilience and marketability of native and commercial fish species. Biosecurity is a constant ontogenesis of novel hypothesis based on current scientific discoveries. To further increase understanding of how parasitism impacts fish health, a systematic literature review was conducted and the pathophysiology of infection described. Potential exposure pathways and parasite host associations in Australia are discussed.

Systematic Evidence Mapping of Potential Exposure Pathways for Per- and Polyfluoroalkyl Substances Based on Measured Occurrence in Multiple Media.

Given that human biomonitoring surveys show per- and polyfluoroalkyl substances (PFAS) to be ubiquitous, humans can be exposed to PFAS through various sources, including drinking water, food, and indoor environmental media. Data on the nature and level of PFAS in residential environments are required to identify important pathways for human exposure. This work investigated important pathways of exposure to PFAS by reviewing, curating, and mapping evidence for the measured occurrence of PFAS in exposure media. Real-world occurrence for 20 PFAS was targeted primarily in media commonly related to human exposure (outdoor and indoor air, indoor dust, drinking water, food, food packaging, articles, and products, and soil). A systematic-mapping process was implemented to conduct title-abstract and full-text screening and to extract PECO-relevant primary data into comprehensive evidence databases. Parameters of interest included the following: sampling dates and locations, numbers of collection sites and participants, detection frequencies, and occurrence statistics. Detailed data were extracted on PFAS occurrence in indoor and environmental media from 229 references and on PFAS occurrence in human matrices where available from those references. Studies of PFAS occurrence became numerous after 2005. Studies were most abundant for PFOA (80% of the references) and PFOS (77%). Many studies analyzed additional PFAS, particularly, PFNA and PFHxS (60% of references each). Food (38%) and drinking water (23%) were the commonly studied media. Most studies found detectable levels of PFAS, and detectable levels were reported in a majority of states in the United States. Half or more of the limited studies for indoor air and products detected PFAS in 50% or more of the collected samples. The resulting databases can inform problem formulation for systematic reviews to address specific PFAS exposure queries and questions, support prioritization of PFAS sampling, and inform PFAS exposure measurement studies. The search strategy should be extended and implemented to support living evidence review in this rapidly advancing area.

1220. Public Health Investigations of Water-Related Organisms in Neonatal Intensive Care Units—United States, 2014–2022

Abstract Background Preterm and critically ill infants cared for in neonatal intensive care units (NICUs) are vulnerable to a wide variety of infections. Water use in healthcare settings is a known risk factor for opportunistic pathogen transmission due to the ability of such pathogens to persist in premise plumbing, though facility water risk assessments may also not account for practices within NICUs. We describe Centers for Disease Control and Prevention (CDC) consultations involving NICU patients and water-related organisms to help inform infection prevention and control response. Methods We searched internal CDC records from January 1, 2014, through December 31, 2021, to identify consultations involving investigations of potential or confirmed transmission of water-related organisms in NICU settings. We used available information to determine number of consultations and patients affected, most common organisms implicated, and potential exposure pathways and transmission routes. Results Of 92 consultations involving NICUs in the United States during the study period, we identified 30 consultations (33%) of water-related organism infections or outbreaks; combined, water-related organisms were isolated from 178 patients during these investigations. Serratia marcescens was the organism reported in the greatest number of investigations (n=10, 33%), followed by Pseudomonas spp. and Burkholderia cepacia complex (each n=4, 13%). Definitive transmission routes were not determined for all consultations, though investigations frequently identified concerns with water use in infant activities of daily living, such as bathing or feeding (n=14, 47%). Examples of such exposures unique to the NICU setting included the use of tap water to remove disinfectant residue from humidified isolettes and storage of supplies rinsed in water in infant bath basins to dry. Conclusion Consultations involving water-related organisms are common in the NICU. While clear sources of transmission are not always found, investigations often identified water exposures that may pose infection risks. To protect critically ill infants, hospitals should account for the extensive and unique characteristics of water use in NICUs when developing water management programs. Disclosures All Authors: No reported disclosures.

Preliminary Evidence of Anticoagulant Rodenticide Exposure in American Kestrels (Falco sparverius) in the Western United States

ABSTRACT Although there is extensive evidence of declines in the American Kestrel (Falco sparverius) population across North America, the cause of such declines remains a mystery. One hypothesized driver of decline is anticoagulant rodenticide (AR) exposure, which could potentially cause mortality or reduced fitness. We investigated AR exposure in wild American Kestrels in Utah, USA. We collected and tested for AR residues in liver samples (n = 8) from kestrels opportunistically encountered dead and in blood samples (n = 71) from live wild kestrels, both nestlings and adults. We found high detection rates in both tissues. Adult kestrels were more likely to exhibit exposure than juveniles sampled in nests. Three-quarters (six of eight) of tested liver samples from adult kestrels exhibited evidence of AR exposure. Additionally, liver samples (n = 19) opportunistically collected from seven species of raptors within our study area had detectable levels of AR residues, with seven of eight raptor species evidencing exposure; across all raptors, five ARs were detected in liver samples, with brodifacoum the most prevalent, being found in over half (14 of 27) of samples. Over half (7 of 12) of the blood samples from adult kestrels had detectible levels of ARs, while only one of 59 juvenile nest samples tested positive. The difference in exposure rates between adults and juveniles could indicate differential exposure pathways by age class. Based on these findings, we recommend that ARs be further investigated as a potential cause of kestrel declines. Future research could focus on expanding sampling to provide sufficient sample sizes to test for potential nonlethal effects of AR exposure (e.g., fecundity, nesting success), identifying potential exposure pathways, and developing methods for passive sampling of ARs in excreta.