Overview
Muhib and colleagues analyzed 90 cow milks from Savar near Dhaka, grouped as packaged branded, dairy farm and household milk, for cadmium, chromium, lead, manganese, copper and iron by flame atomic absorption. Chromium was the highest metal in branded and dairy milk and lead the lowest in every group. Chromium intake from milk exceeded the permissible value used by the authors.
Key numbers
- Lead mean: 0.033 ± 0.006 (branded), 0.015 ± 0.002 (dairy farm), 0.012 ± 0.001 ppm (household); maximum about 0.20 ppm in each group (Table 3).
- Cadmium mean: 0.053 ± 0.022, 0.024 ± 0.009 and 0.047 ± 0.026 ppm (Table 3).
- Chromium mean: 0.672 ± 0.010, 0.373 ± 0.008 and 0.539 ± 0.013 ppm (Table 3).
Methods (brief)
Eight digestion methods were compared and nitric acid with hydrogen peroxide (6 + 1 mL) was used. Metals were read by flame atomic absorption with detection limits of 0.001 to 0.005 mg/kg. Recoveries of 97 to 101% were obtained on stock standard solutions labeled as reference materials.
Evidence Fitness
Moderate sample size across three sources. Many printed standard deviations are mathematically impossible for the printed ranges, which suggests standard errors or misprints, and the flame method’s stated detection limits are optimistic. The packaged milk is not described by fat content, so this is not a measurement of reduced-fat milk.