| Category | Key Agents | Major Sources | Primary Health Concerns |
| Heavy Metals & POPs | Pb, Cd, Hg, As; PCBs, PBDEs, OCPs | Industrial emissions, mining, e-waste, agricultural use | Neurotoxicity, nephrotoxicity, carcinogenicity, endocrine disruption |
| Particulate Matter & Occupational Dust | PM2.5, PM10; coal dust, silica, asbestos | Combustion processes, traffic, construction, mining | Pulmonary fibrosis, copd, lung cancer, cardiovascular effects |
| Emerging Contaminants | Microplastics, PFAS, pharmaceuticals, nanomaterials | Consumer products, wastewater, industrial effluents | Immunotoxicity, hepatotoxicity, reproductive effects (emerging evidence) |
| Food-Related Contaminants | Aflatoxins, acrylamide, pesticide residues, heavy metals | Contaminated crops, processed foods, food packaging | Hepatocellular carcinoma, neurotoxicity, endocrine disruption |