Comp Biochem Physiol C Toxicol Pharmacol. 2015 Jun-Jul;172-173:36-44. doi: 10.1016/j.cbpc.2015.04.005.
The influence of zinc chloride and zinc oxide nanoparticles on air-time survival in freshwater mussels.
- 1Emerging Methods Aquatic Contaminants Research Division, Water Science and Technology, Environment Canada, 105 McGill, Montréal, QC H2Y 2E7, Canada. Electronic address: firstname.lastname@example.org.
- 2Emerging Methods Aquatic Contaminants Research Division, Water Science and Technology, Environment Canada, 105 McGill, Montréal, QC H2Y 2E7, Canada.
- 3Département de Chimie, Université de Montréal, Montréal, QC H2V 2B8, Canada.
The purpose of this study was to determine the cumulative effects of exposure to either dissolved zinc or nanozinc oxide (nanoZnO) and air-time survival in freshwater mussels. Mussels were exposed to each forms of zinc for 96h then placed in air to determine survival time. A sub-group of mussels before and after 7days of exposure to air were kept aside for the determination of the following biomarkers: arachidonate-dependent cyclooxygenase (COX) and peroxidase (inflammation and oxidative stress), lipid metabolism (total lipids, esterases activity, HO-glycerol, acetyl CoA and phospholipase A2) and lipid damage (lipid peroxidation [LPO]). The results showed that air-time survival was decreased from a mean value of 18.5days to a mean value of 12days in mussels exposed to 2.5mg/L of nanoZnO although it was not lethal based on shell opening at concentrations below 50mg/L after 96h. In mussels exposed to zinc only, the median lethal concentration was estimated at 16mg/L (10-25 95% CI). The air-time survival did not significantly change in mussels exposed to the same concentration of dissolved Zn. Significant weight losses were observed at 0.5mg/L of nanoZnO and at 2.5mg/L for dissolved zinc chloride, and were also significantly correlated with air-time survival (r=0.53; p<0.01). Air exposure significantly increased COX activity in control mussels and in mussels exposed to 0.5mg/L of nanoZnO and zinc chloride. The data also suggested fatty acid breakdown and β-oxidation. Mussels exposed to contaminants are more susceptible to prolonged exposure to air during low water levels.
KEYWORDS: Air-time survival; Elliptio complanata; Oxidative stress; inflammation
- The ability of mussels to survive outside of water could be compromised by pollution
- Mussels exposed to zinc oxide nanoparticles survived 6 days less than mussels exposed to zinc chloride or control mussels
- Air exposure significantly increased inflammation and zinc exposures had not influence on this response
- Air exposure also increased fatty acid catabolism and β-oxidation indicative of fasting.