Environmental Pollution and Protection

Number 4, 2018

9
Acetylcholinesterase Activity in Fish Exposed to Mercury in Guanabara Bay, RJ, Brazil

Authors: Ana Paula de Castro Rodrigues, Rodrigo Guerra Carvalheira, Vanessa Gomes, Ana Rosa Linde Arias, Nádia Regina Pereira Almosny, Zuleica Carmen Castilhos, Edison Dausacker Bidone

Abstract

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Acetylcholinesterase (AChE) is an important regulatory enzyme that controls the transmission of nerve impulses across cholinergic synapses. This study evaluated AChE activity as an effect biomarker for ecological risk assessment related to mercury contamination in fish from Guanabara bay, Rio de Janeiro State, Brazil. A total of 30 fishes were collected, 14 specimens of Genidens genidens and 16 specimens of Haemulon sp. at three sampling stations. AChE activity varied from 0.18 to 1.29 μmol min-1 mg-1 protein for G. genidens and a negative correlation between AChE activity in muscles and mercury concentrations in kidney was found (-0.55; p<0.05; n=14). For Haemulon sp. the enzyme activity showed a smaller range (0.06 to 0.22 μmol min-1 mg-1 protein) and a negative correlation between mercury concentrations in muscles and AChE activity was found (r = -0.570; p<0.05; n=16), suggesting a decrease on enzymatic response in specimens with higher mercury bioaccumulation.

9
Agent Orange: A Controversy without End

Authors: Alvin L. Young

Abstract

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Confusion and misinformation are common when discussing Agent Orange, a tactical herbicide used in the Vietnam War. This is partially the result of inaccurate news coverage or false information that is purposely spread to deceive veterans. Sensationalized reporting has frequently left the public with a distorted view of what occurred in Vietnam and of the minimal risks related to the use of herbicides in an operational combat environment. However, such a discrepancy between perceived risks and actual risks has also been enhanced by a public policy where historical records and science have been ignored while favoring a policy of “presumptive” compensation promoted by the Agent Orange Act of 1991. The Act has resulted in a narrow focus on tactical herbicides as the key factor in explaining the health risks of Vietnam veterans, ignoring other important risk factors that occurred in the war in Vietnam, namely, widespread endemic tropical diseases and parasites, psychological and physiological impacts of war, and health and lifestyle. Thus, it is not surprising that the controversies surrounding the use of Agent Orange in Vietnam have raged for 40 years. Indeed, more than a million United States veterans and billions of dollars have been spent by the United States Department of Veterans Affairs in providing compensation and health care for unrelated diseases where the vast majorities are not deployment-related health problems or related to herbicide exposure, but rather to aging and quality of life issues.