Jurowski et al. 2023 — As, Pb, and Cd in green tea infusions from Polish markets
This study measured arsenic, lead, and cadmium in infusions (prepared beverages, not dry leaf) of 12 green tea samples commercially available in Poland, using ICP-MS, and conducted a three-tier toxicological risk assessment (TRA) comparing weekly intake to JECFA provisional tolerable weekly intakes (PTWI). All three metals were detected in all 12 samples. Lead was the dominant contaminant: average Pb (0.891 µg/L infusion) was approximately 2.75–4 times higher than As (0.325 µg/L) and Cd (0.214 µg/L). Samples from China showed higher HMI than samples from Sri Lanka. Under the assessed weekly consumption scenarios (21–70 cups/week), weekly intake per body weight did not exceed PTWI values, indicating no identified health risk at normal green tea consumption.
Key numbers
Heavy metal concentrations in green tea infusions (µg/L, n=12):
- As: minimum 0.0721, maximum 0.585, mean 0.325 (RSD 0.71–5.5%)
- Pb: minimum 0.386, maximum 1.695, mean 0.891 (RSD 1.32–8.22%)
- Cd: minimum 0.126, maximum 0.346, mean 0.214 (RSD 1.91–4.58%)
Note: Abstract states As range is 0.0721–10.585 µg/L; Table 4 (results/discussion) clarifies the actual maximum As was 0.585 µg/L, with the abstract appearing to contain a typographical error in the range upper bound. Use Table 4 values (0.0721–0.585 µg/L) as the correct range.
Country-of-origin effect: all investigated samples from China had higher HMI content than samples from Sri Lanka.
Infusion preparation: 200 mL boiling water per manufacturer instructions; 3–8 minutes brewing time; no added lemon juice or citric acid.
Analytical method: ICP-MS (Elan DRC-e Perkin Elmer); external calibration; two multi-element stock solutions as internal standards. Method validated per prior publications (Jurowski et al. 2021).
Methods (brief)
12 commercially available green tea samples (GT1–GT12) collected from stores in five Polish cities (July–October 2022). Various physical forms: silk/cotton/nylon/paper bags; loose leaf/needle. Infusions prepared per manufacturer instructions. ICP-MS (Elan DRC-e Perkin Elmer, plasma 1150 W). Three-tier TRA: tier 1 — raw HMI profile and descriptive statistics; tier 2 — weekly intake estimate (21–70 cups/week at 200 mL); tier 3 — weekly intake per body weight (70 kg adult) vs PTWI (JECFA). No PTWI exists for Pb currently; comparison used the at-the-time PTWI framework.
Implications
Certification: Green tea infusions contain measurable As, Pb, and Cd; the infusion concentrations are low relative to PTWI but are non-zero. Tea is a high-consumption beverage globally, making cumulative dietary contribution from tea non-trivial at high consumption frequencies. Country-of-origin matters: Chinese-origin samples consistently higher.
Courses: Good example of a three-tier TRA methodology applied to a widely consumed beverage; demonstrates that the infusion (as-consumed) matrix is the relevant measurement for beverage risk assessment, not the dry leaf.
App: Green tea ingredient flag: detectable Pb, As, and Cd in infusions; concentration depends on country of origin (China > Sri Lanka in this dataset); weekly intake is within PTWI bounds at typical consumption levels but not at very high consumption.