Overview
Zgavarogea and colleagues collected 88 samples from water, feed, raw milk, and 10 dairy product categories across two contrasting Romanian dairy systems (traditional Vaideeni and industrial Ibanesti) over five seasonal sampling rounds and analyzed them by ICP-OES for 17 elements. Lead, cadmium, and nickel in potentially toxic elements are the most relevant to this page. Sour cream showed the lowest nickel concentration of all products studied and relatively low cadmium, while lead was moderate. The authors attribute cream’s lower nickel and cadmium to the preferential association of these elements with milk’s protein-rich casein fraction rather than the fat-rich cream fraction.
Key numbers
Raw cow milk, Table 4 (mg/L):
- Vaideeni region mean: lead 0.0165 +/- 0.0063, cadmium 0.0022, nickel 0.0152 mg/L
- Ibanesti region mean: lead 0.0140 +/- 0.0080, cadmium 0.0028, nickel 0.0198 mg/L
- Both regions below EU 2023/915 maximum of 0.020 mg/kg for lead in milk
Dairy products, Table 7 (mg/kg, fresh weight basis):
| Product | n | Lead (mg/kg) | Cadmium (mg/kg) | Nickel (mg/kg) |
|---|---|---|---|---|
| Fresh cheese | 18 | 0.086 | 0.018 | 0.126 |
| Brined hard cheese | 13 | 0.120 | 0.024 | 0.267 |
| Hard cheese | 7 | 0.977 | 0.007 | 0.933 |
| Bellows cheese | 4 | 0.091 | 0.017 | 0.095 |
| Whey cheese | 4 | 0.064 | 0.017 | 0.113 |
| Mozzarella | 4 | 0.182 | 0.011 | 0.124 |
| Sour cream | 4 | 0.099 | 0.012 | 0.081 |
Sour cream (0.081 mg/kg nickel) is the lowest nickel value in the product set. The authors state: “Sour cream exhibited the lowest nickel (Ni) concentration among all investigated products and relative low cadmium (Cd) levels, while lead (Pb) remained moderate. Because sour cream is mainly derived from the fat-rich fraction of milk rather than the casein-rich curd, its elemental profile differs from that of cheese products.”
Dietary exposure estimates for sour cream (Table 8): lead adult EDI 0.057, child EDI 0.099 µg/kg bw/day; cadmium adult 0.007, child 0.012 µg/kg bw/day; nickel adult 0.046, child 0.081 µg/kg bw/day. All below EFSA toxicological reference values.
Methods (brief)
ICP-OES (PlasmaQuant 9100, Analytik Jena; ceramic D-torch, PFA cyclonic spray chamber). Microwave acid digestion: milk 5 mL plus 10 mL 65% HNO3 plus 3 mL 37% HCl, 15-minute ramp to 200 degrees Celsius plus 15-minute hold. Recoveries 84.8 to 105.9 percent; RSD less than 10 percent; R-squared 0.999 to 1.000. Calcium, magnesium, sodium, potassium measured additionally by FAAS.
Evidence fitness
The sour cream subsample is small (n=4), collected from two specific regions in Romania during 2024-2025. Sour cream in Romanian dairy tradition is a fermented cream (similar to creme fraiche) with a fat content around 20 to 25 percent; it is a different product from fresh liquid cream or whipping cream used in Western Europe and North America. The small sample size limits generalizability. The study is multi-season, which is a strength. The comparison across product types within the same study is a key asset for cream versus cheese interpretation. Regional elemental fingerprinting was the primary purpose; contamination profiling is secondary but carefully documented.
Related evidence
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