What heavy metals are in milk products?

December 1, 2025 •

4 min read

According to a 2025 review of studies, lead (Pb) was the most prevalent heavy metal contaminant in milk samples globally, significantly exceeding permissible limits in some regions. This concerning finding raises important questions about what heavy metals are in milk products and the potential health risks for consumers worldwide.

Quick Summary

This article examines the presence of toxic heavy metals, including lead, cadmium, arsenic, and mercury, in various dairy products, detailing their origins, health impacts, and the factors influencing contamination levels. It highlights the importance of monitoring and regulation to ensure consumer safety.

Key Points

Lead (Pb) is a major concern: Multiple global studies have found elevated levels of lead in milk and milk products, sometimes exceeding safety limits, posing significant health risks, particularly for children.
Cadmium (Cd) is highly toxic: Cadmium, found in some phosphate fertilizers and industrial waste, is a potent toxicant that can accumulate in dairy animals and transfer to milk products, concentrating further during cheese-making.
Arsenic (As) and Mercury (Hg) are also present: These heavy metals originate from industrial and environmental sources and can be found in milk, though often at lower concentrations than lead and cadmium.
Concentration increases in processed products: Cheese and especially milk powder can have higher concentrations of heavy metals than raw milk due to the concentration and evaporation processes involved in their production.
Sources include environment and processing: Contamination pathways include polluted soil and water ingested by livestock, atmospheric fallout near industrial areas, and transfer from processing equipment and packaging.
Regulatory monitoring is essential: Ensuring dairy product safety relies on continuous monitoring and enforcement of regulations, as heavy metals pose cumulative risks over long-term consumption.

Common Heavy Metals Found in Milk and Dairy Products

Several heavy metals and metalloids are consistently identified as contaminants in milk and milk products. While naturally occurring in the environment, their concentration can be significantly elevated due to anthropogenic activities. The most common and concerning include lead (Pb), cadmium (Cd), arsenic (As), and mercury (Hg).

Lead (Pb)

Lead is a dangerous heavy metal contaminant due to its chronic toxicity, especially affecting the nervous system in developing infants and young children. Its sources include industrial emissions, vehicular exhaust, contaminated soil, and fertilizers. Dairy animals ingest lead through contaminated water and forage, and it can also enter milk during processing.

Cadmium (Cd)

Cadmium is highly toxic and accumulates in the human body over time. It is significantly more toxic than lead. Sources include phosphate fertilizers, industrial waste, and fossil fuel combustion. Cadmium enters the food chain when livestock consume contaminated feed and water. It can concentrate in cheese due to its affinity for milk proteins.

Arsenic (As)

Both natural and man-made sources contribute to arsenic contamination. Inorganic arsenic is considered more toxic. Sources include industrial waste and contaminated drinking water. Dairy animals ingest arsenic through contaminated water, which can then transfer to their milk.

Mercury (Hg)

Mercury compounds are highly toxic and bioaccumulate. Sources include fossil fuel burning and metal production. Ingestion of contaminated feed and water is the main route. However, dairy animals have efficient elimination mechanisms, often resulting in lower levels in milk compared to other foods.

Factors Influencing Heavy Metal Levels in Dairy Products

The concentration of heavy metals in milk and its products varies based on several factors:

Geographic location: Levels are often higher in areas with intensive industrial, mining, or agricultural activities.
Animal feed and water: Contaminated forage and drinking water are primary pathways.
Agricultural practices: Use of certain fertilizers and pesticides can introduce contaminants into the soil.
Processing and storage: Concentration and evaporation can increase levels, and contamination can occur from equipment or packaging.
Type of milk: Metal concentrations can differ based on animal species and fat content.

Health Risks of Heavy Metal Contamination

Chronic consumption of dairy products with elevated heavy metal levels poses health risks, especially for infants and children. These risks include damage to the nervous system, kidneys, and liver, and increased cancer risk. Lead can cause cognitive deficits, and cadmium can lead to skeletal damage and renal failure. While many levels are below critical thresholds, cumulative exposure increases risk. Regulatory agencies use metrics like the Target Hazard Quotient (THQ) to assess non-carcinogenic risks.

Mitigation Strategies to Reduce Contamination

Ensuring milk safety involves strict oversight and proactive measures throughout the supply chain.

Source Control: Minimizing environmental pollution is key.
Feed and Water Monitoring: Regular testing is crucial, especially near industrial areas.
Improved Farming Practices: Sustainable farming and guidelines on fertilizer/pesticide use help prevent soil contamination.
Regular Testing: Monitoring milk and dairy products ensures compliance with safety standards.
Packaging Control: Using safe materials and ensuring sanitary processing prevents additional contamination.

Comparing Heavy Metal Levels in Milk and Processed Products

Heavy metal concentrations can change during processing, potentially increasing levels. The table below provides a comparison:


Feature	Raw Milk	Cheese (e.g., Kareish)	Milk Powder	Dairy-Derived Yogurt	Dairy-Derived Ice Cream
Lead (Pb) levels	Can be elevated; processing may increase levels.	Significant increase due to binding with milk caseins.	Highest maximum levels often due to concentration.	Can contain elevated levels if flavorings are contaminated.	Potential for elevated levels if raw materials or processing equipment are contaminated.
Cadmium (Cd) levels	Varies based on environmental exposure.	Can be higher than in raw milk, especially if milk proteins bind Cd.	High residual levels reported due to concentration and evaporation.	Generally low but can be affected by contaminated additives.	Generally low but depends on source contamination.
Arsenic (As) levels	Varies globally depending on water and soil quality.	Moderate levels compared to milk powder.	Highest levels often reported in milk powder due to concentration.	Low levels typically found.	Can be present if additives are contaminated.
Contamination Factors	Animal feed, water, and environmental pollution.	Bioaccumulation during cheese-making process.	Concentration and evaporation, and potentially packaging.	Contaminated additives like fruit purees.	Raw materials and processing equipment.

Conclusion

Heavy metals like lead, cadmium, arsenic, and mercury in milk products remain a food safety concern, primarily from environmental pollution and agricultural practices. While levels often meet regulations, elevated concentrations occur in some areas. Vulnerable groups like infants are at higher risk. Continued monitoring, stricter enforcement, and proactive mitigation throughout the supply chain are crucial for public health. Consumers should be aware of product sourcing and potential risks.

Outbound Link

For more information on global food safety standards, including limits for heavy metals in food products, consult the official website for the Codex Alimentarius Commission.

Frequently Asked Questions

The primary source is environmental pollution that contaminates animal feed and water, often originating from industrial emissions, agricultural runoff, and waste disposal. Livestock then ingest these contaminants, which can eventually be transferred to their milk.

Studies show that lead and cadmium levels tend to be higher in milk powder compared to fresh milk. This is because the concentration and evaporation processes used to create milk powder can increase the concentration of any existing contaminants.

Heavy metals, particularly lead and cadmium, can bind to milk proteins such as caseins. During the curdling and processing stages of cheese production, these protein-bound metals get transferred and concentrated in the curd, leading to higher levels in the final cheese product.

No, standard pasteurization and sterilization processes are not effective at removing heavy metals from milk. While these methods eliminate biological and microbial contaminants, they do not impact chemical contaminants like heavy metals.

Infants and young children are considered the most vulnerable population due to their higher rate of milk consumption relative to their body weight. Their developing nervous systems are also more susceptible to the toxic effects of heavy metals like lead.

While organic farming practices may reduce some sources of contamination, they do not guarantee that milk is entirely free of heavy metals. Environmental factors like soil and water pollution can still affect organic farms, and contamination can occur during processing and packaging.

Mitigation requires a multi-faceted approach, including stricter environmental regulations on industrial and agricultural waste, regular monitoring of animal feed and water, improved farming and processing techniques, and careful selection of food-grade packaging materials.