The impact of environmental pollution on food safety mainly forms a systemic threat through three major media: soil, water, and atmosphere. Soil pollution mainly comes from industrial emissions and agricultural activities. Heavy metals such as lead and cadmium, absorbed by crops, can accumulate in the human body for a long time, leading to chronic poisoning and organ damage. The pollution of irrigation water is equally serious. Antibiotics and organic pollutants in industrial wastewater are enriched through the food chain, making aquatic products carriers of chemical pollutants. Air pollutants such as sulfur dioxide and nitrogen oxides settle in the form of acid rain, which not only changes soil pH and affects crop growth, but also directly adheres to the surface of agricultural products, increasing the residue of toxic substances. The migration and transformation of these pollutants in the environment have a chain effect, for example, mercury released from mining activities will first pollute the air, then enter water bodies with rainfall, and ultimately form high concentrations of methylmercury in fish bodies.

The transmission of pollution in the agricultural production process is particularly prominent. Overuse of pesticides leads to persistent pollutants such as organochlorine remaining in the soil for decades, which can cause endocrine disruption and cancer risk when entering crops through roots. Contaminated feed in animal husbandry can lead to the accumulation of heavy metals in poultry and livestock, while vegetables grown around industrial areas often contain excessive levels of cadmium, which may damage kidney function if consumed for a long time. It is worth noting that environmental pollution also has complex effects, such as the significant increase in toxicity when polycyclic aromatic hydrocarbons coexist with heavy metals. These substances are more common in smoked food and contaminated agricultural products.

The harm of environmental pollution to food safety also has intergenerational transmission characteristics. After pregnant women consume food containing pollutants, neurotoxins such as lead can affect fetal brain development through the placental barrier. The destruction of ecosystems can also exacerbate biological pollution, and the toxins produced by the massive reproduction of algae can contaminate shellfish, potentially leading to mass food poisoning incidents. These impacts highlight the inseparable nature of environmental protection and food safety, requiring the control of pollutant emissions from the source and the establishment of a risk monitoring system that runs through the entire food chain.