Toxic trace elements in different brands of milk infant formulae in Nairobi market, Kenya

Overview

This study measured Al, Cd, Pb, and Ni in seven milk-based infant formula powders for infants aged 0-6 months sold in the Nairobi market. The source is direct occurrence evidence for powdered non-soy infant formula in Kenya. Its main HMT&C signal is that Pb was detected in all seven products and exceeded the Kenya Bureau of Standards maximum limit of 0.02 ppm in five of seven anonymized product codes, while Cd was not detected.

Key numbers

Formula powder concentrations (Table 3; ug/g, mean +/- SE, n=9 replicate analyses per code):

Anonymized product code	Al	Cd	Pb	Ni
T	1.054 +/- 0.085	ND	0.018 +/- 0.002	0.032 +/- 0.001
U	2.069 +/- 0.447	ND	0.022 +/- 0.001	0.029 +/- 0.002
V	1.545 +/- 0.089	ND	0.018 +/- 0.001	0.032 +/- 0.002
W	1.099 +/- 0.068	ND	0.059 +/- 0.002	0.031 +/- 0.003
X	2.156 +/- 0.423	ND	0.032 +/- 0.007	0.022 +/- 0.001
Y	1.543 +/- 0.245	ND	0.022 +/- 0.002	0.030 +/- 0.003
Z	1.405 +/- 0.031	ND	0.040 +/- 0.002	0.028 +/- 0.001

Source-reported ranges and exceedance framing:

Al ranged from 1.054 +/- 0.085 ug/g in code T to 2.156 +/- 0.423 ug/g in code X.
Pb ranged from 0.018 +/- 0.001 ug/g in code V to 0.059 +/- 0.002 ug/g in code W.
Ni ranged from 0.022 +/- 0.001 ug/g in code X to 0.032 +/- 0.001 ug/g in code T.
Cd was not detected in any of the seven infant formula products.
The authors state that all codes except T and V had Pb above the KEBS maximum limit of 0.02 ppm.

Estimated weekly intake (Table 4; ug/kg infant body weight):

Anonymized product code	Al	Pb	Ni
T	56.02	2.90	1.72
U	109.98	1.15	1.74
V	82.11	0.98	1.70
W	39.95	2.15	1.11
X	322.07	4.84	3.26
Y	60.58	1.89	2.01
Z	59.32	2.52	2.61
PTWI comparator in source	1000	0.5	35

The paper states that Al and Pb estimated weekly intakes were below the provisional tolerable weekly intake values used by the authors, while still cautioning that Pb exceeded the KEBS formula limit in most product codes.

Methods (brief)

Seven milk-based infant formula powders for infants aged 0-6 months were purchased from Nairobi stores and anonymized as product codes T-Z. Powder samples were digested by weighing 2.5 g into a Kjeldahl flask, adding 15 mL concentrated nitric acid and 5 mL 10% hydrogen peroxide, heating until brown fumes ceased, filtering, and diluting to 50 mL. Al, Cd, Pb, and Ni were measured in triplicate by atomic absorption spectrometry using a Varian AA-10 instrument. Calibration curves had correlation coefficients from 0.9988 to 0.9998, and spike-recovery checks gave 98.1-99.9% recovery.

Implications

Standards work: This source contributes powder-basis occurrence data for Al, Pb, Cd, and Ni in milk-based infant formula from the Nairobi market, with product-level results kept anonymized. The Pb data are especially relevant because the paper reports both product-code concentrations and a KEBS exceedance statement.

Courses: Useful for showing the difference between regulatory-limit exceedance in the product and intake-estimate framing in the same paper.

App: Provides product-basis occurrence fields for Pb, Al, Ni, and Cd in powdered infant formula. The source uses anonymized product codes, not public brand names.

Microbiome: Not addressed.

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Verification notes

Fresh auto-fetch ingest 2026-05-19 from the gap-driven infant-formula wishlist. The same DOI appeared in downloaded wishlist rows targeting Al, Cd, and Ni; this page is the canonical source page for those duplicate downloads.
Strict brand firewall: the source title uses “brands” generically, and the paper anonymizes the products as T-Z. This page preserves only anonymized source codes where needed for numeric fidelity and does not name any commercial brand.
The source reports Cd as not detected; no Cd numeric range is inferred.
Methods vendor/equipment names are retained under Part 12 Exception 2.

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