Risk characterization of microplastics in San Francisco Bay, California
Abstract Assessing microplastics risk to aquatic ecosystems has been limited by lack of holistic exposure data and poor understanding of biological response thresholds. Here we take advantage of two recent advances, a toxicological meta-analysis that produced biotic response thresholds and a method...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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SpringerOpen
2022-07-01
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| Series: | Microplastics and Nanoplastics |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s43591-022-00037-z |
| _version_ | 1811219018830315520 |
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| author | Scott Coffin Stephen B. Weisberg Chelsea Rochman Merel Kooi Albert A. Koelmans |
| author_facet | Scott Coffin Stephen B. Weisberg Chelsea Rochman Merel Kooi Albert A. Koelmans |
| author_sort | Scott Coffin |
| collection | DOAJ |
| description | Abstract Assessing microplastics risk to aquatic ecosystems has been limited by lack of holistic exposure data and poor understanding of biological response thresholds. Here we take advantage of two recent advances, a toxicological meta-analysis that produced biotic response thresholds and a method to quantitatively correct exposure data for sampling methodology biases, to assess microplastic exposure risk in San Francisco Bay, California, USA. Using compartment-specific particle size abundance data, we rescaled empirical surface water monitoring data obtained from manta trawls (> 333 μm) to a broader size (1 to 5000 μm) range, corrected for biases in fiber undercounting and spectroscopic subsampling, and assessed the introduced uncertainty using probabilistic methods. We then compared these rescaled concentrations to four risk thresholds developed to inform risk management for California for each of two effect categories/mechanisms - tissue translocation-mediated effects and food dilution - each aligned to ecologically relevant dose metrics of surface area and volume, respectively. More than three-quarters of samples exceeded the most conservative food dilution threshold, which rose to 85% when considering just the Central Bay. Within the Central Bay, 38% of the samples exceeded a higher threshold associated with management planning, which was statistically significant at the 95% confidence interval. For tissue translocation-mediated effects, no samples exceeded any threshold with statistical significance. The risk associated with food dilution is higher than that found in other systems, which likely reflects this study having been conducted for an enclosed water body. A sensitivity analysis indicated that the largest contributor to assessment variability was associated with estimation of ambient concentration exposure due to correcting for fiber undercounting. Even after compensating for biases associated with fibers and other small particles, concentrations from the trawl samples were still significantly lower than the 1-L grab samples taken at the same time, suggesting our SFB risk estimates are an underestimate. We chose to rely on the trawl data because the 1-L grab sample volume was too small to provide accurate spatial representation, but future risk characterization studies would be improved by using in-line filtration pumps that sample larger volumes while capturing a fuller range of particle size than a towed net. |
| first_indexed | 2024-04-12T07:18:42Z |
| format | Article |
| id | doaj.art-d51acf10c6634fc1a35fe37a6693b106 |
| institution | Directory Open Access Journal |
| issn | 2662-4966 |
| language | English |
| last_indexed | 2024-04-12T07:18:42Z |
| publishDate | 2022-07-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Microplastics and Nanoplastics |
| spelling | doaj.art-d51acf10c6634fc1a35fe37a6693b1062022-12-22T03:42:23ZengSpringerOpenMicroplastics and Nanoplastics2662-49662022-07-012111810.1186/s43591-022-00037-zRisk characterization of microplastics in San Francisco Bay, CaliforniaScott Coffin0Stephen B. Weisberg1Chelsea Rochman2Merel Kooi3Albert A. Koelmans4California State Water Resources Control BoardSouthern California Coastal Water Research Project AuthorityDepartment of Ecology and Evolutionary Biology, University of TorontoAquatic Ecology and Water Quality Management Group, Wageningen UniversityAquatic Ecology and Water Quality Management Group, Wageningen UniversityAbstract Assessing microplastics risk to aquatic ecosystems has been limited by lack of holistic exposure data and poor understanding of biological response thresholds. Here we take advantage of two recent advances, a toxicological meta-analysis that produced biotic response thresholds and a method to quantitatively correct exposure data for sampling methodology biases, to assess microplastic exposure risk in San Francisco Bay, California, USA. Using compartment-specific particle size abundance data, we rescaled empirical surface water monitoring data obtained from manta trawls (> 333 μm) to a broader size (1 to 5000 μm) range, corrected for biases in fiber undercounting and spectroscopic subsampling, and assessed the introduced uncertainty using probabilistic methods. We then compared these rescaled concentrations to four risk thresholds developed to inform risk management for California for each of two effect categories/mechanisms - tissue translocation-mediated effects and food dilution - each aligned to ecologically relevant dose metrics of surface area and volume, respectively. More than three-quarters of samples exceeded the most conservative food dilution threshold, which rose to 85% when considering just the Central Bay. Within the Central Bay, 38% of the samples exceeded a higher threshold associated with management planning, which was statistically significant at the 95% confidence interval. For tissue translocation-mediated effects, no samples exceeded any threshold with statistical significance. The risk associated with food dilution is higher than that found in other systems, which likely reflects this study having been conducted for an enclosed water body. A sensitivity analysis indicated that the largest contributor to assessment variability was associated with estimation of ambient concentration exposure due to correcting for fiber undercounting. Even after compensating for biases associated with fibers and other small particles, concentrations from the trawl samples were still significantly lower than the 1-L grab samples taken at the same time, suggesting our SFB risk estimates are an underestimate. We chose to rely on the trawl data because the 1-L grab sample volume was too small to provide accurate spatial representation, but future risk characterization studies would be improved by using in-line filtration pumps that sample larger volumes while capturing a fuller range of particle size than a towed net.https://doi.org/10.1186/s43591-022-00037-zMicroplasticsEnvironmental risk assessmentProbability density functionsMarine ecosystemsEstuarine ecosystemsManagement framework |
| spellingShingle | Scott Coffin Stephen B. Weisberg Chelsea Rochman Merel Kooi Albert A. Koelmans Risk characterization of microplastics in San Francisco Bay, California Microplastics and Nanoplastics Microplastics Environmental risk assessment Probability density functions Marine ecosystems Estuarine ecosystems Management framework |
| title | Risk characterization of microplastics in San Francisco Bay, California |
| title_full | Risk characterization of microplastics in San Francisco Bay, California |
| title_fullStr | Risk characterization of microplastics in San Francisco Bay, California |
| title_full_unstemmed | Risk characterization of microplastics in San Francisco Bay, California |
| title_short | Risk characterization of microplastics in San Francisco Bay, California |
| title_sort | risk characterization of microplastics in san francisco bay california |
| topic | Microplastics Environmental risk assessment Probability density functions Marine ecosystems Estuarine ecosystems Management framework |
| url | https://doi.org/10.1186/s43591-022-00037-z |
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