| NSF Org: |
CBET Division of Chemical, Bioengineering, Environmental, and Transport Systems |
| Recipient: |
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| Initial Amendment Date: | March 17, 2017 |
| Latest Amendment Date: | July 27, 2017 |
| Award Number: | 1709939 |
| Award Instrument: | Standard Grant |
| Program Manager: |
Karl Rockne
krockne@nsf.gov (703)292-7293 CBET Division of Chemical, Bioengineering, Environmental, and Transport Systems ENG Directorate for Engineering |
| Start Date: | April 1, 2017 |
| End Date: | March 31, 2020 (Estimated) |
| Total Intended Award Amount: | $49,951.00 |
| Total Awarded Amount to Date: | $55,951.00 |
| Funds Obligated to Date: |
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| History of Investigator: |
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| Recipient Sponsored Research Office: |
1320 SOUTH DIXIE HIGHWAY STE 650 CORAL GABLES FL US 33146-2919 (305)284-3924 |
| Sponsor Congressional District: |
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| Primary Place of Performance: |
FL US 33146-2926 |
| Primary Place of
Performance Congressional District: |
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| Unique Entity Identifier (UEI): |
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| Parent UEI: |
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| NSF Program(s): | EnvE-Environmental Engineering |
| Primary Program Source: |
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| Program Reference Code(s): |
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| Program Element Code(s): |
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| Award Agency Code: | 4900 |
| Fund Agency Code: | 4900 |
| Assistance Listing Number(s): | 47.041 |
ABSTRACT
1709939
Solo-Gabriele
The first transmission of the mosquito-borne Zika virus in the continental U.S. was discovered August 2016 in Miami-Dade County, Florida. Efforts have been mounted to eradicate the mosquito vectors; however, some of these efforts, including insecticide sprays, have been viewed with skepticism by local communities due to limited knowledge and inconsistent information concerning the fate of the insecticide and the subsequent ecological and human health impacts. Thus, there are growing concerns about the human health and ecological impacts of insecticide spraying, especially Naled spraying in Miami. Those against Naled's use emphasize that Naled has negative health and ecosystem impacts impacting honeybees and birds and was banned by the European Union in 2012. Those proposing continued use of Naled cite studies that suggest it is safe to use according to specifications (in ultra-low volume). The objective of this project is to develop an understanding of the environmental fate of Naled by conducting laboratory-controlled experiments supplemented by full-scale opportunistic monitoring during aerial spray activities.
Specifically, this study will evaluate the impact of soil and water on the persistence of Naled and its by-product, Dichlorvos, both of which have insecticidal properties. The laboratory study will be supplemented with sampling conducted before and after the spray of Naled in the coming summer season, to identify potential areas of accumulation within the coastal intertidal zone. The PI's team will evaluate the persistence of environmental insecticides; specifically, they will evaluate the impacts of sediment properties on the fate of Naled and Dichlorvos and assess whether the intertidal zone serves as a reservoir of insecticide accumulation. The existing literature sheds little light on the fate of Naled and degradation by-products in natural settings. Moreover, scant data are available on the impacts of environmental matrices, especially sediments, on the persistence of Naled. The PI will evaluate Naled as a model organophosphate insecticide which is currently the insecticide of choice for Zika larvae eradication. They hypothesize that the persistence of Naled in the environment varies across environmental media, e.g., shorter persistence in beach sands than the soils with higher organic content. They further hypothesize that Naled from the aerial sprays in coastal areas will accumulate in the intertidal zone, allowing for potential exposures nearshore. Results from this study can be used to quantify decay rates for Naled under different soil conditions. These decay rates will be validated against measurements collected during full-scale spray activities. Results can be incorporated into fate and transport models that simulate Naled persistence in the environment. The Miami-Dade community will benefit from the translation of the knowledge gained from this project to mosquito control decisions by Miami-Dade County's Mosquito Control Division, and from assessments of human health risks by the Miami-Dade Department of Health.
PUBLICATIONS PRODUCED AS A RESULT OF THIS RESEARCH
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PROJECT OUTCOMES REPORT
Disclaimer
This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.
Naled, an organophosphate pesticide, received considerable attention during 2016 as it was applied aerially to control the first mosquito-borne Zika virus outbreak in the continental United States. Stakeholders living in affected areas raised concerns about its environmental impacts. One factor influencing environmental impacts is how long does the chemical remain in the environment after an aerial spray activity.
The intellectual merit of this study was to evaluate the persistence of naled and its degradation bi-product, dichlorvos in natural waters. Initial naled concentrations were measured at ground level after full-scale aerial spray activities. Laboratory experiments were designed to evaluate factors (fresh versus marine water chemistry, temperature, and sunlight) that may promote the degradation of naled and dichlorvos in the environment. Results show that natural fresh and marine water chemistry promoted naled degradation as experiments with de-ionized water resulted in half-lives greater than 6 days. The half-life in natural waters without light ranged from 5 to 20 hours with lower half lives at higher temperatures. Under light exposure, degradation was accelerated and yielded more dichlorvos. Detectable levels (0.05 micromolar for naled and 0.10 micromolar for dichlorvos) were measured in water samples collected from the field during aerial spray events.
The broader impacts of this study is that results can be used in risk assessments that consider both naled and dichlorvos to better understand ecological impacts and to develop improved public health recommendations. For example by understanding how long the chemical remains in the environment after an aerial spray, guidance can be developed for the time periods people need to remain indoors to minimize exposures.
Last Modified: 07/29/2020
Modified by: Helena Solo-Gabriele
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