For decades, the world has been plagued by pervasive food contamination. Access to safe food is fundamental to sustaining life, thus constituting a basic human right. Across the globe, billions of individuals are vulnerable to unsafe food, resulting in millions falling ill and hundreds of thousands succumbing annually. The journey of food from its origin on the farm to its consumption on the plate is filled with challenges encompassing microbial, chemical, personal, and environmental hygiene concerns. 

Heavy Metals: A Silent Threat 

Heavy metal contamination of food is an emerging threat to food safety, particularly in developing countries where uncontrolled pollution is prevalent.  These metals are non-biodegradable water-soluble contaminants with long biological half-lives.  Cobalt (Co), copper (Cu), nickel (Ni), iron (Fe), manganese (Mn), zinc (Zn), molybdenum (Mo), and selenium (Se) are essential nutrients for living organisms, yet exceeding their safe limits in consumption can lead to severe health issues (Munir et al., 2021). Conversely, metals like arsenic (As), cadmium (Cd), chromium, and lead (Pb) are non-essential to human health and can cause significant health problems even at low levels of exposure. 

Impact of Urbanisation and Industrialisation

Recent developments like increased urbanisation and industrial development, especially in densely populated and developing nations, have implicated heavy metals as one of the prominent factors responsible for food intoxication. In recent years, various heavy metal contaminants have been documented to detrimentally influence crop quality and seafood, consequently impinging on food security and human health (Munir et al., 2021). 

Sources of Heavy Metal Contamination

Contamination with these metals often results from industrial emissions, usage of contaminated water for irrigation, and improper handling during harvesting, storage, and sale. In addition, poor waste disposal and excessive use of chemical fertilisers or pesticides lead to heavy metal contamination in soil and water. Unfortunately, polluted rivers degrade biodiversity, affecting species like fish and human health through fish consumption. Plants and fish from these contaminated sources accumulate these metals, posing a risk of heavy metal intoxication to humans who consume them. These metals enter the food chain through biochemical pathways and undergo bioaccumulation, and biomagnification across the food chain, posing a threat to human health.

The Public Health Impact of Heavy metals Contamination

While crucial for maintaining homeostasis, many heavy metals present in water, air, and soil can cause severe biological and cellular damage to humans and other organisms. Heavy metals accumulate in human skeletal and adipose tissues, depleting essential nutrients and causing a range of disorders affecting the central nervous system, heart, blood, liver cells, kidneys, neural development, reproduction, and immunity, along with intrauterine growth retardation. 

Eateries contaminated with heavy metals have a progressive and detrimental impact on human health due to their persistent nature. Consuming contaminated crops can lead to several short-term, as well as, long-term adverse health effects such as headache, fatigue, drowsiness, confusion, muscular pain, skin irritations, unusual pigmentation and keratosis, hypertension, gastroenteritis, cardiovascular disease, lung edema, destruction of mucous membranes, intravascular hemolysis, memory loss, renal dysfunction, Alzheimer’s disease, respiratory diseases, etc. 

Excessive metals can bypass body mechanisms leading to cellular dysfunction ultimately resulting in toxic and potentially fatal outcomes (Vanisree et al., 2022). They are also known for their mutagenic, carcinogenic, genotoxic, and neurotoxic properties (Pande et al., 2022).

Mitigating the Risks of Heavy Metal Contamination

Contamination with heavy metals significantly undermines the health benefits of consuming fruits, crops, and vegetables. Addressing the risks of heavy metal contamination in food crops requires a carefully planned strategy. Enhancing food security requires reducing contamination sources through stringent laws and regulations and adopting best agricultural practices. Given the limited arable land, it is crucial to refrain from planting near industrial and mining sites. 

Additionally, evaluating heavy metal accumulation in soil and crops is essential to minimise public health risks from consuming contaminated produce. Biological remediation techniques, such as phytoremediation, offer an eco-friendly and cost-effective approach to mitigate heavy metal toxicity in mildly contaminated soils. 

Addressing environmental pollution by reducing heavy metal contamination and adopting sustainable agricultural practices is essential for safeguarding public health and ensuring long-term food security (Munir et al., 2021). By implementing secure measures and utilising advanced technologies, along with raising awareness among farmers about the dangers of heavy metal, we can significantly promote food safety and public health.

References 

Munir, N., Jahangeer, M., Bouyahya, A., El Omari, N., Ghchime, R., Balahbib, A., … & Shariati, M. A. (2021). Heavy metal contamination of natural foods is a serious health issue: A review. Sustainability, 14(1), 161.

Pande, V., Pandey, S. C., Sati, D., Bhatt, P., & Samant, M. (2022). Microbial interventions in bioremediation of heavy metal contaminants in agroecosystem. Frontiers in microbiology, 13, 824084.

Vanisree, C. R., Sankhla, M. S., Singh, P., Jadhav, E. B., Verma, R. K., Awasthi, K. K., … & Nagar, V. (2022). Heavy metal contamination of food crops: Transportation via food chain, human consumption, toxicity and management strategies. In Environmental Impact and Remediation of Heavy Metals. IntechOpen.