Assessment of persistent, bioaccumulative and toxic substances (PBTS) and sublethal effects in giant toads from Coatzacoalcos Veracruz, Mexico Chapter uri icon

abstract

  • The Coatzacoalcos River Basin is one of the most important hydrological and ecological regions of Mexico. The Coatzacoalcos estuary has experienced a fast industrial and urban growth which combined with other productive activities such as agriculture and cattle farming have triggered a severe impact in the region%27s ecosystems. Persistent organic pollutants (POPs) and lead have been identified in several environmental matrices in the region. So far, few efforts have been made to evaluate exposure and effects on wildlife in the area. Amphibian populations have been recognized as biomonitors of changes in environmental conditions. The purpose of this chapter is to present the synthesized main research found, through assessment of exposure biomarkers and sublethal effects in giant toads specimens collected from the Coatzacoalcos River downstream. Lead levels in the blood of toads range from 10.8 to 70.6 μg/dL and are significantly higher in industrial sites. We have found a significant decrease of the δ-ALAD activity in blood measuring 35.3 to 78%25 for the urban-industrial and industrial sites, respectively. In addition, we have identified a strong inverse relationship between the δ-ALAD activity and the levels of lead found in blood (r=- 0.84, p<0.001). Total POPs levels in soil and toad tissues range from 660.5-2,712.9 ng/g d.w. to 55.6-1,2471.9 ng/g l.w., respectively. Differences in POP%27s levels by site type have not been found. DNA damage found in blood ranges from 0.7 to 4.8 (Olive tail moment) and 7.4 to 16.7 μm (Tail length). DNA damage has been found to be higher at industrial zones compared to urban zones. Our results suggest that the Rhinella marina can be considered as a good biomonitor of DNA damage and δ-ALAD activity inhibition. This study provides a data baseline on the PBTs pollution status in soil and giant toads of Coatzacoalcos River downstream, in Veracruz. © 2014 by Nova Science Publishers, Inc. All rights reserved.
  • The Coatzacoalcos River Basin is one of the most important hydrological and ecological regions of Mexico. The Coatzacoalcos estuary has experienced a fast industrial and urban growth which combined with other productive activities such as agriculture and cattle farming have triggered a severe impact in the region's ecosystems. Persistent organic pollutants (POPs) and lead have been identified in several environmental matrices in the region. So far, few efforts have been made to evaluate exposure and effects on wildlife in the area. Amphibian populations have been recognized as biomonitors of changes in environmental conditions. The purpose of this chapter is to present the synthesized main research found, through assessment of exposure biomarkers and sublethal effects in giant toads specimens collected from the Coatzacoalcos River downstream. Lead levels in the blood of toads range from 10.8 to 70.6 μg/dL and are significantly higher in industrial sites. We have found a significant decrease of the δ-ALAD activity in blood measuring 35.3 to 78%25 for the urban-industrial and industrial sites, respectively. In addition, we have identified a strong inverse relationship between the δ-ALAD activity and the levels of lead found in blood (r=- 0.84, p<0.001). Total POPs levels in soil and toad tissues range from 660.5-2,712.9 ng/g d.w. to 55.6-1,2471.9 ng/g l.w., respectively. Differences in POP's levels by site type have not been found. DNA damage found in blood ranges from 0.7 to 4.8 (Olive tail moment) and 7.4 to 16.7 μm (Tail length). DNA damage has been found to be higher at industrial zones compared to urban zones. Our results suggest that the Rhinella marina can be considered as a good biomonitor of DNA damage and δ-ALAD activity inhibition. This study provides a data baseline on the PBTs pollution status in soil and giant toads of Coatzacoalcos River downstream, in Veracruz. © 2014 by Nova Science Publishers, Inc. All rights reserved.

publication date

  • 2014-01-01