Co-exposure of carbon nanotubes with carbofuran pesticide affects metabolic rate in Palaemon pandaliformis (shrimp)

Palaemon pandalirformis (shrimp) is a species widely distributed in the Brazilian coastal region and with an important economic role. In addition, this organism is considered an indicator of environmental pollution in estuaries; however, its physiological responses to toxic environmental pollutants, including pesticides and nanomaterials, are not well known, mainly, the effects of co-exposure. Thus, the purpose of this study was to evaluate the ecotoxicological effects of co-exposure between oxidized multiwalled carbon nanotubes (HNO3MWCNT) and carbofuran pesticide on the routine metabolism of P. pandalirformis. The shrimps were exposed to different concentrations of HNO3-MWCNT (0; 10; 100; 500; 1000 mu g L-1), carbofuran (0; 0.1; 1.0; 5.0; 10 mu g L-1) and to co-exposure with 100 mu g L-1 of HNO3-MWCNT + carbofuran (0; 0.1; 1.0; 5.0; 10 mu g L-1), to evaluate the effects on metabolic rate (O2 consumption) and excretion of ammonia (NH4+NH3). Our results showed that the shrimps exposed to HNO3-MWCNT (10 mu g L-1) increased the metabolic rate by 292% and the excretion of ammonia by 275%; those exposed to carbofuran (10 mu g L-1) increased their metabolic rate by 162% and the excretion of ammonia by 425%; and with the co-exposure of HNO3-MWCNT + carbofuran there was also an increase in the metabolic rate by 317% and an excretion of ammonia by 433% when compared to control. These findings provides useful information toward better understanding the physiological responses of shrimps after combined exposure to nanomaterials and pesticides in aquatic environments.

Automated summary

This study evaluated the ecotoxicological effects of co-exposure of oxidized multiwalled carbon nanotubes and carbofuran pesticide on the routine metabolism of P. pandalirformis. Results showed that both pollutants had impacts on the shrimps' metabolic rate and ammonia excretion, highlighting the importance of understanding physiological responses to combined exposure in aquatic environments.