Clinical Pharmacist and Master’s student in Clinical Pharmacy with research interests in pharmacovigilance, behavioral interventions in mental health, and AI applications in clinical decision support. Experience includes digital health research with Bloomsbury Health (London) and pharmacovigilance practice in patient support programs. Published work covers drug awareness among healthcare providers, postpartum depression management, and patient safety reporting. 
Clinical Pharmacist and Master’s student in Clinical Pharmacy with research interests in pharmacovigilance, behavioral interventions in mental health, and AI applications in clinical decision support. Experience includes digital health research with Bloomsbury Health (London) and pharmacovigilance practice in patient support programs. Published work covers drug awareness among healthcare providers, postpartum depression management, and patient safety reporting. What was reviewed?
This review article comprehensively examines the sources, environmental behavior, and toxicological impacts of heavy metals in terrestrial and aquatic ecosystems. The focus keyphrase, heavy metal contamination and its impact on the environment, is central to the analysis, which details the chemical forms, persistence, bioaccumulation, and regulatory frameworks for metals such as arsenic, cadmium, chromium, lead, mercury, copper, zinc, nickel, antimony, and selenium. The review synthesizes findings regarding the distribution of these metals in soil, water, and air, the pathways through which contamination occurs, and the molecular mechanisms underlying their genotoxic and carcinogenic effects. The article also discusses the essentiality and toxicity thresholds of these elements, highlighting the delicate balance between necessary physiological roles and harmful exposures, a key consideration for any heavy metal certification program.
Who was reviewed?
The review draws upon a wide range of studies involving both environmental samples and biological organisms. It references research on contaminated water, soil, and air, as well as investigations into bioaccumulation in plants, aquatic life, and human tissues. Populations considered include those residing in industrial, agricultural, and urban regions where exposure risk is elevated due to anthropogenic activities. The review also incorporates epidemiological and toxicological data from vulnerable groups such as children, pregnant women, and occupationally exposed workers, as well as wildlife and aquatic organisms impacted by environmental contamination. This broad, interdisciplinary scope underscores the widespread relevance of heavy metal contamination and its impact on the environment for both regulatory and public health perspectives.
Most important findings
| Critical Points | Details |
|---|---|
| Heavy metals are persistent, bioaccumulative, and toxic | Metals such as Cd, Pb, Hg, Cr, As accumulate in the environment, enter food webs, and resist degradation, leading to chronic exposure risks for humans and wildlife. |
| Sources of contamination are both natural and anthropogenic | Mining, industrial emissions, improper waste management, fertilizers, and natural events like volcanic eruptions all contribute to environmental loading. |
| Soil, water, and air serve as primary reservoirs and transmission pathways | Heavy metals contaminate crops, groundwater, drinking water, and air particulates, resulting in exposure through ingestion, inhalation, and dermal contact. |
| Health effects are metal-specific and dose-dependent | Cadmium accumulates in kidneys, mercury causes neurotoxicity, lead impairs neurological development in children, and arsenic is carcinogenic, among others. |
| Regulatory limits exist but are inconsistently enforced or region-specific | Agencies like EPA, FDA, and WHO have set permissible limits for heavy metals in water and food, but global enforcement and monitoring still vary widely. |
| Bioaccumulation and biomagnification amplify risks in food chains | Heavy metals can concentrate up the food chain, especially in aquatic ecosystems, increasing exposure risks for top predators and humans consuming contaminated fish. |
| Essential heavy metals have a narrow margin between nutritional adequacy and toxicity | Elements like copper and zinc are vital at low concentrations but harmful when limits are exceeded, necessitating precise risk assessment and certification. |
| Environmental and human health impacts necessitate stringent monitoring and certification | Regular assessment of heavy metal levels in environmental matrices and food products is critical to minimize health risks and ensure regulatory compliance. |
Key implications
The review underscores the urgent necessity of adopting comprehensive, science-based heavy metal testing and certification standards. For certification bodies, detailed knowledge of contamination sources, environmental persistence, and regulatory thresholds is essential in developing protocols that protect both human and ecological health. Regular monitoring, risk assessment, and updating certification criteria based on emerging toxicological evidence are critical for public safety and international trade compliance.
Citation
MathuMitha C., Mohan Raj V., Sangeetha R., Susan George, & Ragumaran M. (2021). A review on the effect of heavy metal contamination and its impact on the environment. International Journal of Zoological Investigations, 7(2), 762-771. https://doi.org/10.33745/ijzi.2021.v07i02.061
Heavy metals are high-density elements that accumulate in the body and environment, disrupting biological processes. Lead, cadmium, arsenic, mercury, nickel, tin, aluminum, and chromium are of greatest concern due to persistence, bioaccumulation, and health risks, making them central to the HMTC program’s safety standards.
Cadmium is a persistent heavy metal that accumulates in kidneys and bones. Dietary sources include cereals, cocoa, shellfish and vegetables, while smokers and industrial workers receive higher exposures. Studies link cadmium to kidney dysfunction, bone fractures and cancer.
Lead is a neurotoxic heavy metal with no safe exposure level. It contaminates food, consumer goods and drinking water, causing cognitive deficits, birth defects and cardiovascular disease. HMTC’s rigorous lead testing applies ALARA principles to protect infants and consumers and to prepare brands for tightening regulations.
