Winiarska-Mieczan et al. 2022 - cadmium and lead in instant coffee products
This Polish market-basket study measured cadmium and lead in 49 instant coffee, instant coffee drink, and coffee-substitute products purchased in eastern Poland. The study is direct occurrence evidence for instant coffee products, and contextual evidence for coffee substitutes that do not yet have a dedicated HMT&C product page. The source anonymized product samples by code; this wiki page reports only category-level aggregate values.
Key numbers
Cd and Pb concentrations by product group (Table 3; microgram/kg product as sold; average of three analytical replicates):
| Product group | n | Cd mean | Cd max | Cd min | Cd median | Pb mean | Pb max | Pb min | Pb median |
|---|---|---|---|---|---|---|---|---|---|
| Instant coffee | 11 | 0.095 | 0.137 | 0.067 | 0.085 | 82.64 | 88.81 | 73.22 | 86.73 |
| Green and roasted instant coffee blend | 6 | 0.549 | 0.732 | 0.358 | 0.585 | 70.94 | 85.12 | 54.32 | 69.82 |
| Cappuccino instant coffee | 6 | 0.030 | 0.070 | <LOQ | 0.040 | 25.42 | 27.54 | 22.34 | 26.01 |
| Chicory instant drink | 6 | 3.202 | 4.319 | 2.289 | 3.024 | 41.85 | 48.91 | 35.82 | 41.03 |
| Chicory and coffee instant drink | 5 | 2.820 | 4.012 | 1.987 | 2.471 | 11.00 | 13.33 | 9.010 | 10.25 |
| Instant cereal coffee drink | 7 | 3.072 | 3.580 | 2.653 | 2.840 | 41.00 | 44.69 | 38.78 | 39.98 |
| 2-in-1 or 3-in-1 instant coffee | 8 | 0.195 | 0.351 | 0.124 | 0.151 | 12.52 | 13.22 | 11.87 | 12.38 |
Cd differed significantly by product group (ANOVA P=0.003 for means). The highest mean Cd was in chicory instant drink (3.202 microgram/kg), followed by instant cereal coffee drink (3.072 microgram/kg) and chicory/coffee instant drink (2.820 microgram/kg). The lowest Cd means were in cappuccino instant coffee (0.030 microgram/kg) and instant coffee (0.095 microgram/kg).
Pb also differed significantly by product group (ANOVA P=0.002 for means). Instant coffee had the highest mean Pb (82.64 microgram/kg), followed by green/roasted instant coffee blends (70.94 microgram/kg). Chicory/coffee instant drink had the lowest mean Pb (11.00 microgram/kg), and 2-in-1/3-in-1 instant coffee was similarly low (12.52 microgram/kg).
Consumption-risk calculations (Table 4; adult 70 kg body weight; one, two, or three servings/day):
| Consumption pattern | Highest Cd EWI | Highest Cd %TWI | Highest Pb EWI | Highest Pb %BMDL10 | Highest HI |
|---|---|---|---|---|---|
| 1 serving/day | 0.135 microgram/week, chicory instant drink | 0.077% | 2.521 microgram/week, cappuccino | 0.818% | 0.109, cappuccino |
| 2 servings/day | 0.270 microgram/week, chicory instant drink | 0.155% | 5.042 microgram/week, cappuccino | 1.637% | 0.218, cappuccino |
| 3 servings/day | 0.406 microgram/week, chicory instant drink | 0.232% | 7.562 microgram/week, cappuccino | 2.455% | 0.328, cappuccino |
The authors concluded that Cd and Pb intake indicators from these beverages were low under the modeled patterns: in no case did THQ or HI exceed 1. They nevertheless flagged Pb as the more important contributor because Pb concentrations were higher than Cd concentrations and larger serving sizes for some multi-ingredient instant coffee drinks increased modeled Pb intake.
Methods (brief)
The study analyzed 49 instant coffee and coffee-substitute products bought in Chelm, Zamosc, and Lublin, Poland, in August 2019. Product categories and sample counts were: instant coffee (n=11), green/roasted instant coffee blend (n=6), cappuccino instant coffee (n=6), chicory instant drink (n=6), chicory/coffee instant drink (n=5), instant cereal coffee drink (n=7), and 2-in-1/3-in-1 instant coffee (n=8). The paper lists sample codes and product-form descriptors, but this wiki page does not reproduce sample-code rows.
Samples were manually mixed, and approximately 3 g was weighed in triplicate into heat-sterilized china crucibles. Samples were dry-mineralized in a muffle furnace at 550°C with hydrogen peroxide as antioxidant; ash was dissolved in 10 mL 1 M nitric acid. Cd and Pb were measured by ICP-MS using a Varian 820 MS Mass Spectrometer. Calibration used Cd and Pb standards; verification used blank 1 M nitric acid and certified reference materials INCT-TL-1 Tea Leaves and INCT-MPH-2 Mixed Polish Herbs. Reported recovery was 95-103%, with precision 6.04 for Cd and 6.07 for Pb. LODs were 0.004 microgram/kg for Cd and 0.005 microgram/kg for Pb; LOQs were 0.01 microgram/kg for Cd and 0.030 microgram/kg for Pb.
Risk estimates modeled one, two, and three servings per day over 365 days. The authors used a 70 kg adult body weight, Cd TWI 2.5 microgram/kg body weight/week, Pb BMDL01 10.5 microgram/kg body weight/week, Pb BMDL10 4.4 microgram/kg body weight/week, Cd RfD 1 microgram/kg body weight/day, and Pb RfD 3.5 microgram/kg body weight/day.
Implications
Standards work: This source provides direct Cd and Pb occurrence values for instant coffee products as sold. It also shows that non-coffee substitute beverage powders can carry a different metal pattern: chicory and cereal coffee substitutes had the highest Cd means, while 100% instant coffee had the highest Pb mean.
Courses: Useful for separating product-form routing from consumption-risk modeling. Per-kg occurrence is highest for Pb in instant coffee, but modeled weekly Pb intake was highest for cappuccino because serving mass is larger.
App: Supports coffee category context for Cd/Pb, with an explicit caveat that coffee substitutes may need separate product handling if Karen approves a dedicated product row.
Microbiome: Not addressed.
Wiki pages this source may touch
Verification notes
- Fresh auto-fetch ingest 2026-05-18 from the gap-driven wishlist. The Cd-target and Pb-target PDF downloads have identical SHA-256 hashes, so the duplicate wishlist DOI is represented as a single source page with
near_duplicates. - Product-scope gap: the paper measures chicory and cereal coffee substitutes in addition to instant coffee. No dedicated
coffee-substitutesproduct slug exists, so this page routes only to coffee and surfaces a new-product proposal for Karen review. - Strict brand firewall: the paper’s Table 2 uses anonymized product codes and product-form descriptors. This page reports category-level aggregates only and does not reproduce sample-code rows or any commercial brand names.
- Methods vendor/reference-material names are retained under Part 12 Exception 2 for instrument, reagent, and certified-reference-material documentation.
Page history
The five most recent substantive edits to this page. The full version history lives in git; when DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.