Clarifying the absence of evidence regarding human health risks to microplastic particles in drinking-water: High quality robust data wanted

In a recently published article, Leslie and Depledge (2020) raise concerns regarding statements on the risk that microplastic particles represent to human health and which have been attributed to reports published by both the Science Academies’ Group, Science Advice for Policy (SAPEA) (part of the European Commission’s Science Advice Mechanism) and the World Health Organization (WHO) (SAPEA. Science Advice for Policy by European Academies, 2019, WHO, 2019). Leslie and Depledge (2020), for instance, suggest that WHO (2019) conclude that there is ‘no evidence to indicate a human health concern.’ This statement, taken out of context from the WHO report (WHO, 2019), is then used to imply that the WHO conclude there is ‘no risk’ related to the exposure of microplastic particles (Leslie and Depledge, 2020). While, Leslie and Depledge (2020) highlight the importance of debate and systematic assessment of claims related to the assessment of risk, observations that we agree are important to highlight, there are a number of points raised in the article that require clarification

Pharmaceuticals and personal care products in the environment: What are the big questions?

Background: Over the past 10-15 years, a substantial amount of work has been done by the scientific, regulatory, and business communities to elucidate the effects and risks of pharmaceuticals and personal care products (PPCPs) in the environment. Objective: This review was undertaken to identify key outstanding issues regarding the effects of PPCPs on human and ecological health in order to ensure that future resources will be focused on the most important areas. Data sources: To better understand and manage the risks of PPCPs in the environment, we used the "key question" approach to identify the principle issues that need to be addressed. Initially, questions were solicited from academic, government, and business communities around the world. A list of 101 questions was then discussed at an international expert workshop, and a top-20 list was developed. Following the workshop, workshop attendees ranked the 20 questions by importance. Data synthesis: The top 20 priority questions fell into seven categories: a) prioritization of substances for assessment, b) pathways of exposure, c) bioavailability and uptake, d) effects characterization, e) risk and relative risk, f) antibiotic resistance, and g) risk management. Conclusions: A large body of information is now available on PPCPs in the environment. This exercise prioritized the most critical questions to aid in development of future research programs on the topic.Centro de Investigaciones del Medioambient

Characterizing and quantifying chemical ingredient use in consumer products between two separate databases and implications for environmental and human health exposure

Assessing chemical exposure in home and personal care products (HPCPs) represents an important data need. Key challenges to the assessment are related to limited knowledge in quantifying and characterizing the weight-fraction inclusion level and functionality of chemicals in HPCPs. Publicly available tools have been developed to address these challenges, such as the Chemical and Products database (CPDat). This study aims to evaluate the relative performance of CPDat by comparing estimates of weight-fraction inclusion level and functionality to other relevant data sources. Specifically, estimates obtained from CPDat are evaluated and compared with estimates obtained from marketing analytic data, using Euromonitor Passport for 31 commonly used chemicals found in HPCPs. The results obtained from this exercise suggest relatively good agreement between each of the methods for 10 chemicals (ρ = 0.92; P-value =0.02). When considering all 31 chemical ingredients, however, the correlation observed is generally poor (ρ = 0.46; P-value = 0.1), which is attributed to differences in how the underlying data are obtained for each method. With an emphasis on obtaining data based on mining datasheets for individual products, the application of CPDat is suggested to be useful for higher tiers of assessment, with data obtained from marketing analytics providing valuable input to exposure-based screening models. The insight gained from this study can be used to help guide the appropriate use of data obtained from different sources within a tiered exposure assessment

A thermodynamic approach for assessing the environmental exposure of chemicals absorbed to microplastic

The environmental distribution and fate of microplastic in the marine environment represents a potential cause of concern. One aspect is the influence that microplastic may have on enhancing the transport and bioavailability of persistent, bioaccumulative, and toxic substances (PBT). In this study we assess these potential risks using a thermodynamic approach, aiming to prioritize the physicochemical properties of chemicals that are most likely absorbed by microplastic and therefore ingested by biota. Using a multimedia modeling approach, we define a chemical space aimed at improving our understanding of how chemicals partition in the marine environment with varying volume ratios of air/water/organic carbon/polyethylene, where polyethylene represents a main group of microplastic. Results suggest that chemicals with log KOW \u3e 5 have the potential to partition \u3e1% to polyethylene. Food-web model results suggest that reductions in body burden concentrations for nonpolar organic chemicals are likely to occur for chemicals with log KOW between 5.5 and 6.5. Thus the relative importance of microplastic as a vector of PBT substances to biological organisms is likely of limited importance, relative to other exposure pathways. Nevertheless, a number of data-gaps are identified, largely associated with improving our understanding of the physical fate of microplastic in the environment. © 2011 American Chemical Society

Environmental fate and exposure models: advances and challenges in 21st century chemical risk assessment

Twenty-five years of progress in modeling the environmental fate and exposure of organic contaminants is reviewed, and a strategy for more rapidly adopting scientific progress into regulatory models is proposed

Field testing passive air samplers for current use pesticides in a tropical environment

Air was sampled for one year in the central valley of Costa Rica using an active high-volume sampler as well as passive samplers (PAS) based on polyurethane foam (PUF) disks and XAD-resin filled mesh cylinders. Extracts were analyzed for pesticides that are either banned or currently used in Costa Rican agriculture. Sampling rates for PUF-based passive air samplers, determined from the loss of depuration compounds spiked on the disks prior to deployment, averaged 5.9 +- 0.9 m3 · d-1 and were higher during the windier dry seasonthan duringthe rainy season. Sampling ratesforthe XADbased passive sampler were determined from the slopes of linear relationships that were observed between the amount of pesticide sequestered in the resin and the length of deployment, which varied from 4 months to 1 year. Those sampling rates increased with decreasing molecular size of a pesticide, and their average of 2.1 +- 1.5 m3 · d-1 is higher than rates previously reported for temperate and polar sampling sites. Eventhoughthetrends ofthe sampling rate with molecular size and temperature are consistent with the hypothesis that molecular diffusion controls uptake in passive samplers, the trends are much more pronounced than a direct proportionality between sampling rate and molecular diffusivity would suggest. Air concentrations derived by the three sampling methods are within a factor of 2 of each other, suggesting that properly calibrated PAS can be effective tools for monitoring levels of pesticides in the tropical atmosphere. In particular, HiVol samplers, PUF-disk samplers, and XADbased passive samplers are suitable for obtaining information on air concentration variability on the time scale of days, seasons and years, respectively. This study represents the first calibration study for the uptake of current use pesticides by passive air samplers.El aire se muestreó durante un año en el valle central de Costa Rica utilizando un muestreador activo de alto volumen, así como muestreadores pasivos (PAS) basados en discos de espuma de poliuretano (PUF) y cilindros de malla rellenos de resina XAD. Se analizaron los extractos para detectar plaguicidas prohibidos o utilizados actualmente en la agricultura costarricense. Las tasas de muestreo de los muestreadores pasivos de aire basados en PUF, determinadas a partir de la pérdida de compuestos de depuración que se espolvorearon en los discos antes de su despliegue, fueron en promedio de 5,9 +- 0,9 m3 - d-1 y fueron mayores durante la estación seca más ventosa que durante la estación lluviosa. Las tasas de muestreo para el muestreador pasivo basado en XAD se determinaron a partir de las pendientes de las relaciones lineales que se observaron entre la cantidad de plaguicida secuestrado en la resina y la duración del despliegue, que varió de 4 meses a 1 año. Esas tasas de muestreo aumentaron con la disminución del tamaño molecular del plaguicida, y su media de 2,1 +- 1,5 m3 - d-1 es superior a las tasas comunicadas anteriormente para los lugares de muestreo templados y polares. Aunque las tendencias de la tasa de muestreo con el tamaño molecular y la temperatura son coherentes con la hipótesis de que la difusión molecular controla la absorción en los muestreadores pasivos, las tendencias son mucho más pronunciadas que una proporcionalidad directa entre la tasa de muestreo y la difusividad molecular sugeriría. Las concentraciones en el aire derivadas de los tres métodos de muestreo están dentro de un factor de 2 entre sí, lo que sugiere que los PAS debidamente calibrados pueden ser herramientas eficaces para controlar los niveles de plaguicidas en la atmósfera tropical. En particular, los muestreadores HiVol, los muestreadores de disco PUF y los muestreadores pasivos basados en XAD son adecuados para obtener información sobre la variabilidad de la concentración en el aire en la escala temporal de días, estaciones y años, respectivamente. Este estudio representa el primer estudio de calibración de la captación de plaguicidas de uso corriente por muestreadores pasivos de aire.Universidad Nacional, Costa Rica.Universidad de Toronto, Canadá.Universidad de Alaska FairbanksInstituto Regional de Estudios en Sustancias Tóxica