Overview
Nie and colleagues collected 775 orchard samples of apple, pear, peach, grape and jujube at harvest in 2014 across 118 counties in China’s main producing provinces and measured lead, cadmium, chromium and nickel by graphite furnace AAS. They report summary statistics per fruit, single-factor and integrated pollution indices and target hazard quotients. Arsenic and mercury were not measured.
Key numbers
- Jujube (n = 94): lead mean 0.0246 mg/kg (SD 0.0224, median 0.0159); cadmium mean 0.0029 mg/kg; nickel mean 0.1035 mg/kg (Table 7).
- Peach (n = 137): lead mean 0.0277 mg/kg (SD 0.0275), the highest of the five fruits (Table 7).
- Grape (n = 137): lead mean 0.0117 mg/kg, cadmium mean 0.0013 mg/kg (Table 7).
- Lead exceeded 0.1 mg/kg in 0.4% of samples (apple and peach only); nickel exceeded 0.3 mg/kg in 2.2% (Section 3.1).
Methods (brief)
Each sample (10 fruits, five bunches of grapes or 1 kg of jujube) came from five trees in one orchard and was washed and homogenized. Wet digestion with nitric acid and hydrogen peroxide, then graphite furnace AAS; LODs 5, 0.1, 2 and 2.8 ug/kg for lead, cadmium, chromium and nickel. Plant reference material GBW10052 with each batch of 20. Results below the LOD were set to half the LOD before statistics.
Evidence Fitness
Large, well-documented orchard survey with stated QA. It gives medians, means, SDs and 95% upper confidence limits, but no minimum, maximum or per-province values, and the basis is not stated. Jujube, pear, peach and grape are direct evidence for the jujube-fruit and non-apple-fruit pages; single fruits are only a proxy for fruit-mixed, which is not linked.