Settleable atmospheric particulate matter induces stress and affects the oxygen-carrying capacity and innate immunity in Nile tilapia (Oreochromis niloticus)

SOARES, MICHELLY PEREIRA; DE ANGELIS, CAROLINA FERNANDES; CARDOSO, ISRAEL LUZ; MCKENZIE, DAVID J.; DA COSTA SOUZA, IARA; WUNDERLIN, DANIEL A.; MONFERRÁN, MAGDALENA V.; FERNANDES, MARISA NARCISO; LEITE, CLÉO ALCANTARA COSTA

COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. TOXICOLOGY & PHARMACOLOGY

ELSEVIER SCIENCE INC

Año: 2022 vol. 257

1532-0456

Steel industry emissions of atmospheric particulate matter are responsible for air to water cross-contamination, which deposits metal/metalloid contaminants in aquatic ecosystems. This source of contamination has not been considered in most of the environmental monitoring protocols. Settleable atmospheric particulate matter (SePM) collected in an area of steel industry influence was used to analyze the sublethal effects on the hematological and innate immunological variables in Nile tilapia (Oreochromis niloticus) after short-term exposure (96 h). Blood samples were analyzed to evaluate the oxygen-carrying transport capacity, innate immune activity and stressbiomarkers after exposure to ecologically relevant concentration of SePM. The exposure reduced blood oxygencarrying capacity by lessening hematocrit, hemoglobin, erythrocyte, and mean corpuscular hemoglobin concentration. Compensatory increments in mean corpuscular volume and mean corpuscular hemoglobin have also been observed. The contaminant impacted the immune system by reducing the number of leukocytes, thrombocytes, and monocytes, total plasma protein, leukocyte respiratory activity, and by increasing lysozyme concentration. Furthermore, the contaminant caused endocrine stress response, raising plasma cortisol and glucose.Therefore, the alterations caused by SePM threatened the capacity of sustaining aerobic metabolism, impaired the immune system, and changed the energy allocation due to both stress response and immune effect. This may have important implications for the impact of SePM on aquatic ecosystems. Future investigations should assess SePM impact on general physiology and aerobic performance, especially to face common ecological challenges such as hypoxia and sustained swimming. These results point out the need to develop proper protocols to addressthe air-to-water cross-contamination risks by iron ore processing industries.