Hazards of Heavy Metals Contamination


Wardah Razzaq, Green Blogger

Heavy metals are natural elements in the lithosphere which enter human food through industrial or agricultural activities in the form of fertilizers and pesticides. Heavy metals are the root cause of various problems in human body. Loss of bones, kidneys  damage, vascular disorders,   developmental  abnormalities  and  cancer  are  some  of  the well-known  health  problems  associated  with the  heavy metals contamination. Furthermore, these heavy metals are widely scattered in the environment, exhibiting slow but toxic effects on the humans and surroundings due to their biological and non-biodegradable nature. Heavy metals such as iron, copper and zinc at low concentrations are vital to maintain the metabolism of the body and they also play a significant function in various biochemical and physiological functions occurring in the anatomy of the living organisms.

However, heavy metals become harmful when they exceed certain limit. They are an important atmospheric contaminant and their poisonous nature is a matter of concern for the biological, developmental, beneficial and atmospheric concern. They enter the atmosphere by natural as well as man-made activities. They originate from the washing away of soil by water, surface runoff  of rain water created by urbanization, natural break down of the rocks,  quarrying,  industrial and  household waste  and  pesticides which  are used for destroying insects or other organisms  harmful to cultivated plants. Atmospheric ejection, animal dung, irrigation with the contaminated water, weed killers, use of fertilizers and household waste management activities are the important causes of the trace metals contamination in soil. Mercury pollution takes place in the soil due to coal-fired power plants emissions and this emission is the main source of the mercury pollution in the soil.

In addition, rapid industrialization due to the urbanization and an increase in the rate of the population in the developing countries such as India and China are the main causes of heavy metals pollution. The contamination of all the food stuffs by heavy metals is a significant parameter from food safety concern. They are present in the food chain and prevail in different concentrations in human food.

Likewise, traces of heavy metals contaminants are also present in the food waste. Food  waste  includes  the  residues of  different foods  like   rice grains,  breads  as well as  leafy  vegetables. It also includes the stuff   which are associated with the daily intake of different food items like chop sticks, tissue papers and many more. These are the sources of heavy metals contamination in the foods like, trace metals such as cadmium, chromium and lead are present in them. It has been seen that the levels of trace metals even in the minute amounts can cause noxious effects on the health of the humans and its surroundings.  

 Iron is one of the naturally occurring metal which exists in the crust of earth. Mining activities are a root cause of the iron contamination in the drinking water. Sulphuric acid  is  produced  due  to  the  discharge of the ferrous ions that are  formed due to the addition of the oxygen in the iron ores which are abundantly present  in the coal . The  production of  the  free  hydrogen  radicals  by  iron in different processes damages the cells and  DNA  structure  thus  resulting in genetic disorders which can further  turn  into  many  diseases.

Moreover, methyl mercury is the most dangerous form of the mercury. It accumulates in the fishes and the consumption of the fishes is the major route of this form of mercury into the humans. The severe mercury poisoning causes memory problems and fatigue.

In addition, cadmium is a metal which  is present  in  the surroundings through naturally occurring  phenomenas  like  volcanic explosion and some man made activities such as welding,  quarrying,  smoking,  burning of  household waste and usage of fertilizers. It causes effects on the health of the workers working in the vicinity of an industrial area or the people inhabiting that area. It can cause both short term and long term effects. It is noxious to kidneys and causes kidney diseases. It causes adverse effects in the pregnant ladies such as it results in the premature births and reduces the birth weights.

Likewise, lead is a very noxious metal. The extensive use of it has resulted in alot of atmospheric pollution and effects on the human health in various regions of the world. The causes of the increasing  lead exposure  includes  mainly  anthropogenic sources such as industrial processes, consumption of poisonous food and drinking water, smoking and household sources. In the past it was widely used in the gasoline and house paints. The effects of the lead on the human health include loss of appetite, sleeplessness, arthritis, hallucinations and vertigo.

Similarly,  there  are also  many  sources of  arsenic poisoning such as drinking water which gets  polluted  by the use of substances which are used for destroying insects or other organisms harmful to cultivated plants, naturally  occurring mineral deposits or improper discharge of  poisonous  chemicals  in the drinking water. Arsenic contamination particularly affects the skin in man.

Solutions to prevent heavy metals contamination and pollution

Following steps can be opted to get rid of the toxicity of heavy metals contamination:

·         Regular monitoring of all other heavy metals should be emphasized.

·         Regulatory guidelines on heavy metals in the different and various food items by the relevant authorities in the manufacturing of wheat flours and other bakery products should be given.

·         The controlled use of fertilizers and pesticides should be encouraged to prevent heavy metals contamination in the food items. 

·         Use of clean milling plates for the milling processes to prevent heavy metals leaching and cross contamination and prohibits the use of contaminated water for the irrigation of the crops.

About the Author: Wardah Razzaq is a graduate of environment from PU, Lahore. She is an environmentalist, environmental writer and climate activist. She is also envisioned to raise awareness among the people related to different environmental issues and committed at guiding and making the people aware that how they can become the responsible citizens of Pakistan sustainably and environmental friendly through my writings. She further says that it is our responsibility to protect our environment so we, should protect it. She loves to write on nature, environment and climate.










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