Overview
Market survey (retail purchase of five garri samples) with xrf elemental screen and microplastic analysis of Garri (fermented, pressed, fry-toasted cassava granules) as sold: four white garri (one unpackaged open-market, three packaged) and one yellow (palm-oil) garri, packaged.. Growing area or market: Purchase markets: S1 open market, Sango Ota (Ogun State, Nigeria); S2 supermarket, Abuja (Nigeria); S3 halal shop, Shin-Ōkubo (Tokyo, Japan); S4 and S5 halal shop, Shinjuku (Tokyo), ordered online. Growing/production origin not stated per sample; Japanese-market garri described as ‘mainly imported from West Africa’.. Collection period: not reported. Method: Garri oven-dried at 105 °C for 6 h; 50 g sieved to 500 µm; EDXRF (Horiba XGT-5000), single-point analysis on sample taped to holder, 50 kV, 400 s; calibrated with CRM CJ-2 (simulated Asian mineral dust).. Basis: Dry weight: ‘PTEs analysis was conducted directly on the dried garri samples’ after oven-drying at 105 °C (p. 3, p. 5). Table 2 unit mg/g..
Key numbers
white garri (as sold, unpackaged, open market): chromium mean 0.07±0.06a (S1: White garri from open market in Nigeria — Sango Ota, Ogun State, Nigeria (open market; unpackaged/openly vended); Table 2 ‘Distribution of PTEs in all garri samples (n = 3)…’, row chromium (Cr), column S1 (This study, mg/g); p. 12; sample description Table 1, p. 3); nickel mean 1.07±1.17a (S1: White garri from open market in Nigeria — Sango Ota, Ogun State, Nigeria (open market; unpackaged/openly vended); Table 2 ‘Distribution of PTEs in all garri samples (n = 3)…’, row nickel (Ni), column S1 (This study, mg/g); p. 12; sample description Table 1, p. 3).
white garri (as sold, packaged): chromium mean 0.07±0.06a (S2: White garri (packaged) from supermarket in Nigeria — Abuja, Nigeria (supermarket; packaged); Table 2 ‘Distribution of PTEs in all garri samples (n = 3)…’, row Cr, column S2 (This study, mg/g); p. 12; sample description Table 1, p. 3); chromium mean 0.03±0.06b (S3: White garri (packaged) from market in Japan — Shin-Ōkubo, Tokyo, Japan (halal shop; packaged; origin stated only as ‘mainly imported from West Africa’); Table 2 ‘Distribution of PTEs in all garri samples (n = 3)…’, row Cr, column S3 (This study, mg/g); p. 12; sample description Table 1, p. 3); chromium mean 0.03±0.06b (S4: White garri (packaged) from market in Japan — Shinjuku, Tokyo, Japan (halal shop, ordered online; packaged; origin stated only as ‘mainly imported from West Africa’); Table 2 ‘Distribution of PTEs in all garri samples (n = 3)…’, row Cr, column S4 (This study, mg/g); p. 12; sample description Table 1, p. 3); nickel mean 1.03±1.21a (S2: White garri (packaged) from supermarket in Nigeria — Abuja, Nigeria (supermarket; packaged); Table 2 ‘Distribution of PTEs in all garri samples (n = 3)…’, row Ni, column S2 (This study, mg/g); p. 12; sample description Table 1, p. 3); nickel mean 0.23±0.21b (S3: White garri (packaged) from market in Japan — Shin-Ōkubo, Tokyo, Japan (halal shop; packaged; origin stated only as ‘mainly imported from West Africa’); Table 2 ‘Distribution of PTEs in all garri samples (n = 3)…’, row Ni, column S3 (This study, mg/g); p. 12; sample description Table 1, p. 3); nickel mean 1.17±0.55a (S4: White garri (packaged) from market in Japan — Shinjuku, Tokyo, Japan (halal shop, ordered online; packaged; origin stated only as ‘mainly imported from West Africa’); Table 2 ‘Distribution of PTEs in all garri samples (n = 3)…’, row Ni, column S4 (This study, mg/g); p. 12; sample description Table 1, p. 3).
yellow garri (palm-oil garri; as sold, packaged): chromium not detected ND* (S5: Yellow garri (packaged) from market in Japan — Shinjuku, Tokyo, Japan (halal shop, ordered online; packaged, 1 kg; origin stated only as ‘mainly imported from West Africa’); Table 2 ‘Distribution of PTEs in all garri samples (n = 3)…’, row Cr, column S5 (This study, mg/g); p. 12; sample description Table 1, p. 3); nickel mean 0.57±0.50c (S5: Yellow garri (packaged) from market in Japan — Shinjuku, Tokyo, Japan (halal shop, ordered online; packaged, 1 kg; origin stated only as ‘mainly imported from West Africa’); Table 2 ‘Distribution of PTEs in all garri samples (n = 3)…’, row Ni, column S5 (This study, mg/g); p. 12; sample description Table 1, p. 3).
Limitations
Reported Cr (up to 0.07 mg/g = 70 mg/kg) and Ni (0.23-1.17 mg/g = 230-1,170 mg/kg) are orders of magnitude above typical food values; unit ‘mg/g’ is internally confirmed by the authors’ Fe/Zn conversions, so either the EDXRF quantification (mineral-dust calibration, single point, taped dried granules) is invalid for this matrix or the unit is wrong throughout. Values should not be used as occurrence estimates without independent confirmation. No LOD for EDXRF; S5 Cr ‘ND’ cannot be bounded. Text gives Ni range ‘0.23 to 1.21 mg/g’ but Table 2 maximum mean is 1.17 (1.21 is the S2 SD). Table 4 Ni EDIs: adult values (e.g. S1 1.9E-03) do not equal C x 800 g / 70,000 g (1.22E-02) while child values do; S3 adult Ni EDI printed 0.0E+00. Cr EDIs reproduce. Collection/purchase dates not reported. lead (Pb), cadmium (Cd), arsenic (As), mercury (Hg), aluminum (Al), tin (Sn) and uranium (U) were not reported (EDXRF element list limited to Cr, Mn, Fe, Co, Ni, Cu, Zn), so their absence is not evidence of absence. Production/growing origin of the Japan-bought samples not stated beyond ‘mainly imported from West Africa’.