Ecotoxicological assessment of the micelle encapsulator F-500

Using large amounts of firefighting foams releases per- and polyfluoroalkyl substances (PFAS) into estuarine environments: A baseline study in Latin America

We analyzed per- and polyfluoroalkyl substances (PFAS) in aqueous film-forming foams (AFFFs) used to extinguish a major fire in a petrochemical terminal from the Port of Santos (Brazil). Eight AFFFs from seven known commercial brands and one unknown sample (AFFF-1 to AFFF-8) were evaluated. 17 PFAS were identified and quantified using high performance liquid chromatography (LC/MS). The concentrations of Σ17 PFAS in the AFFFs ranged from 500 to 9000 ng/g, with prevalence of short chain PFAS (~85 %), followed by long chain PFAS. Perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), included in the global treaty of the Stockholm Convention, were also detected. We estimated that at least 635.96 g of PFAS were introduced in the estuary, representing a massive input of these substances. This investigation reports the PFAS composition of AFFFs used in firefighting in the GRULAC Region (Group of Latin American and Caribbean countries).

Fire Suppression Agents Combined with Gasoline in Aquatic Ecosystems: A Mixture Approach

Fire suppression agents are recommended for extinguishing fires by flammable liquids and frequently end in water bodies, combined with the fuels. There is a lack of toxicity information on these commercial formulations and the effects of mixtures of fire suppression agents and fuels. The aim of the present study was to evaluate the toxic effects of different fire suppression agents, the gasoline water-soluble fraction (GWSF), and mixtures of each fire suppression agent and GWSF. Individual tests were performed with Daphnia similis and Artemia sp.; the most toxic fire suppression agents to D. similis and Artemia sp. were F-500®, Cold Fire®, Agefoam®, and Kidde Sintex® 1%; the GWSF was the least toxic. The concentration addition model was used to predict the mixture effects and evaluate synergism/antagonism, dose ratio dependence, and dose level dependence. Cold Fire with GWSF showed dose level deviation to D. similis, marked mainly by synergism; for Artemia sp., the dose ratio pattern was predicted, with a synergistic response mainly by Cold Fire. Agefoam and GWSF behaved additively for D. similis and dose ratio for Artemia sp., with synergism being caused by Agefoam. Kidde Sintex 1% with GWSF were dose ratio for both organisms, with Kidde Sintex 1% being responsible for synergism. Our results show that some mixtures of fire suppression agents and GWSF may cause toxicity to aquatic organisms, posing risk in a real environmental scenario, such as a major fire combat. Environ Toxicol Chem 2021;40:767-779. © 2020 SETAC.

Deterministic risk assessment of firefighting water additives to aquatic organisms

Past firefighting water additives were found to contain perfluorinated compounds that could persist in the environment resulting in potential adverse effects to biota. Since this revelation, manufacturers have introduced alternative firefighting water additives that are fluorine free, but few studies have investigated the fate and effects in the environment of these new additives. Firefighting water additives could enter aquatic ecosystems through run-off, leaching or direct application. Therefore, there is a need to investigate the potential effect that firefighting water additives could have on aquatic biota. This study investigated the toxicity of six firefighting water additives: Eco-Gel™, Thermo-Gel™, FireAde™, Fire-Brake™, Novacool Foam™, and F-500™ to aquatic biota. The toxicities of firefighting water additives to Lemna minor (duckweed), Daphnia magna (water flea), Hexagenia spp. larvae (mayfly), Lampsilis fasciola (wavy-rayed lampmussel) and Oncorhynchus mykiss (rainbow trout) were investigated through acute and chronic static and semi-static tests to estimate LC50 values for survival and EC50 values for immobility and/or reproduction endpoints. A large variation in toxicities among the firefighting water additives and among the test species was observed. Based on a worst-case exposure scenario of direct application, several firefighting water additives were found to pose a hazard to aquatic organisms. An exposure rate representative of a direct overhead application by a water bomber during a forest fire was used in the hazard assessment. For example, the hazard quotients determined for the D. magna acute toxicity tests ranged from 0.20 for Eco-Gel to 317 for F-500 in the forest pool (15 cm) scenario. This study presents the first deterministic risk assessment of firefighting water additives in aquatic ecosystems.

Assessment of the Antimicrobial Activity of Algae Extracts on Bacteria Responsible of External Otitis

External otitis is a diffuse inflammation around the external auditory canal and auricle, which is often occurred by microbial infection. This disease is generally treated using antibiotics, but the frequent occurrence of antibiotic resistance requires the development of new antibiotic agents. In this context, unexplored bioactive natural candidates could be a chance for the production of targeted drugs provided with antimicrobial activity. In this paper, microbial pathogens were isolated from patients with external otitis using ear swabs for over one year, and the antimicrobial activity of the two methanol extracts from selected marine (Dunaliella salina) and freshwater (Pseudokirchneriella subcapitata) microalgae was tested on the isolated pathogens. Totally, 114 bacterial and 11 fungal strains were isolated, of which Staphylococcus spp. (28.8%) and Pseudomonas aeruginosa (P. aeruginosa) (24.8%) were the major pathogens. Only three Staphylococcus aureus (S. aureus) strains and 11 coagulase-negative Staphylococci showed resistance to methicillin. The two algal extracts showed interesting antimicrobial properties, which mostly inhibited the growth of isolated S. aureus, P. aeruginosa, Escherichia coli, and Klebsiella spp. with MICs range of 1.4 × 10⁹ to 2.2 × 10¹⁰ cells/mL. These results suggest that the two algae have potential as resources for the development of antimicrobial agents.