Overview
Hungerford and colleagues measured 26 elements, including lead, cadmium, arsenic and mercury, in 212 honeys bought in Queensland or online and compared urban, peri-urban, rural and blended honeys. Toxic metals were mostly low, with two rural honeys carrying high lead alongside high zinc. Origin class made no significant difference for lead, cadmium, zinc, iron or chromium.
Key numbers
- Lead, all honeys: mean 0.0286 mg/kg (SD 0.074), median 0.009 mg/kg, range 0.0025 to 0.69 mg/kg (Table 1).
- Cadmium, all honeys: mean 0.0031 mg/kg, range up to 0.053 mg/kg; median below the LOR of 0.005 mg/kg (Table 1).
- Arsenic and mercury maxima 0.009 and 0.0079 mg/kg; most samples were below the LOR (Table 1).
- Mean lead by origin: blend 0.012, rural 0.045, peri-urban 0.029, urban 0.025 mg/kg (Table 2).
- Two rural honeys had lead 0.69 and 0.63 mg/kg with zinc 120 and 86 mg/kg (Section 4.1).
Methods (brief)
About 1 g of honey was digested with nitric acid in a microwave system and analyzed by ICP-MS for trace elements; major minerals were run by ICP-OES after hot block digestion. Limits of reporting were 10 times the SD of 20 blanks (0.005 mg/kg for lead, cadmium, arsenic and mercury). Certified and in-house reference materials were run, with recoveries in a supplement not included in the filed PDF. Statistics set results below the LOR to half the LOR, so several printed means and medians sit below the LOR.
Evidence Fitness
A large retail survey (n = 212) with good analytical QA, direct evidence for honey. Arsenic is total arsenic. Low-end statistics rest on half-LOR substitution and are stored as censored. Honey is a proxy for pancake-syrup, not that food, so the record does not link the pancake-syrup page.