Burn Pit-related Smoke Causes Acute Irritant Responses in Zebrafish that Vary by Fuel Type
Citation:
Strader, R., S. Padilla, Yong Ho Kim, D. Hunter, J. Smoot, K. Britton, B. Knapp, W. Oshiro, M. Hazari, M. Hays, W. Preston, I. jaspers, Matthew Gilmour, AND A. Farraj. Burn Pit-related Smoke Causes Acute Irritant Responses in Zebrafish that Vary by Fuel Type. 18th International Congress on Combustion Byproducts and Health Effects, Durham, NC, May 19 - 21, 2024.
Impact/Purpose:
The impacts of burn pit smoke in humans and aquatic species remain uncertain despite emerging evidence pointing to adverse effects. These findings for the first time demonstrate that burn pit smoke related fuel types cause irritant responses in zebrafish. Importantly, zebrafish exhibit irritant responses to the same chemicals that elicit lung irritation in mammals. In addition, the type of material burned plays a major role in the magnitude and quality of toxicity. These findings may increase biological plausibility for the handful of studies linking inhalation to adverse effects.
Description:
Combustion of mixed materials during open air burning of refuse and housefires produces emissions that worsen air and water quality and cause adverse health effects. The purpose of this study was to assess the irritant potential of extractable organic material of smoke condensates derived from the combustion of 5 different lab-generated burn pit smoke material types (plywood, cardboard, plastic, mixture, and mixture plus diesel) in a glass tube furnace. Irritant locomotor responses were measured in zebrafish (Danio rerio) larvae, a model that demonstrate irritant effects to chemicals that are analogous to mammals. It was hypothesized that smoke-induced locomotor responses, measures of irritant effects, might be dependent upon fuel type. To test this, locomotor activity was tracked for 60 min in 6-day-old zebrafish larvae immediately after exposure to 0.4% dimethyl sulfoxide (DMSO) vehicle or burn pit extracts (0.4–40 μg/ml; half-log intervals). Preliminary data indicates that both plastic and cardboard elicited concentration-dependent irritant responses as indicated by increased locomotor activity. At the highest concentration, plastic was overtly toxic, causing a sedative-like effect, whereas cardboard was irritating but not overtly toxic. At lower concentrations, plastic produced similar or greater irritant effects than cardboard at equal concentrations. Locomotor assessments of the remaining fuel types are forthcoming. These initial findings indicate that burn pit-related smoke has the potential for irritating effects that are likely influenced by material type burned (Abstract does not reflect U.S. EPA policy; DoD award #W811XWH-18-1-0731(IJ)).