Fish Contamination and its Effect on Human Health
By Dr. Rayees Ahmad Bhat
A number of harmful substances e.g. pesticides, hydrocarbons and heavy metals are released into the aquatic environment. Upon receiving a large quantity of contaminants there is an immediate impact on aquatic life which results in large-scale sudden mortalities of aquatic organisms, e.g. fish, prawns etc. While the lower levels of the pesticides result in an accumulation of the pollutants in aquatic organisms. Bioaccumulation of pesticides in the fish results in immunosuppression, reduced metabolism, and damage to gills and epithelia, fin/tail rot, gill disease, hyperplasia, liver damage, neoplasia and ulceration. A number of surveys have indicated a greater proportion of diseases in fish in polluted environment than non-polluted environment. Water pollution and fish contamination are acute and chronic public health hazards. “Globally, a huge population with estimation of over one billion people rely on fish and other seafood as their main source of animal proteins.,” Eating healthy fish like salmon, herring, macherel or sardines reduces the risk of dying from heart attack by 36%. The omega 3-fatty acids in fish protects the heart against development of potentially deadly cardiac rhythm disturbances. It also helps in lowering blood pressure, improve blood vessel function and ease inflammation. American Heart Association and others suggest that everyone should eat fish twice a week. But unfortunately the contaminants in rivers and lakes affect not only fish and other aquatic animals but also water resources, and ultimately our personal health and economies. Contaminants like Methylmercury and persistent organic pollutants (POPs), (PCBs), dioxin, and chlorinated pesticides have adverse effect on human health, especially in developing human fetus and infant. A number of studies have revealed that persistent organic pollutants (POPs) causes developmental, immune, and/or cognitive deficits in newborns. In addition to this, these contaminants affect the central nervous system, the reproductive system, liver and cancer. It is worth noting that eating contaminated fish does not make people sick right away. The more contaminated fish, the greater amount of chemicals will build in the body with time. And among all contaminants, mercury is a contaminant of particular concern, causes developmental problems in children, memory, impairs learning ability.
Future prospectives
A general awareness in public needs to be addressed related to the benefits and risks of eating fish. People should be eduacated related to risk of contaminated fish and fish with low contamination needs to be choosed. Shark, swordfish, king mackerel need not to be consumed as they contain high level of mercury. Large predatory fish also should be avoided as they contain high levels of methyl mercury.
State planning and policy coordination: It is important to address the source and the contaminants of the water. Regular monitoring and effective pollution control can minimize the drastic consequences.
Incorporate public health into protection of ecosystems and water quality. Programs that focus on ecosystem protection and restoration need to be expanded to address the public health dimensions of environmental problems and potential solutions.
Promote public demand for safer and sustainably harvested fish. Better information about fish sources and quality will promote consumer actions. Actions such as asking grocers and restaurants where their fish are from can help discourage the catching and selling of fish that are endangered or nonecologically farmed.
Potential risk of fish intake must be considered in the context of potential benefits. Water pollution and fish contamination remain a serious problem and pose a risk to human health. Policy makers need to make fish contamination a priority, and coordinated statewide action is essential to addressing these problems regionally and nationally. Avoidance of contaminated fish consumption could result in saving thousands of excess deaths annually and suboptimal neurodevelopment in children.
The author is Research Scholar (Zoology, Kurukshetra University, Kurukshetra) and can be reached at: bhatrayees8@gmail.com
