Bangladesh MICS7 shows high lead in 38.5% of children

A medRxiv preprint by Syed Toushik Hossain posted Oct. 11 found elevated blood lead in 38.5% of 10,622 Bangladeshi children aged 12-59 months in 2025 MICS7 data.

Hossain's preprint matters because prevalence increased from 30.2% in the poorest wealth quintile to 51.9% in the richest, challenging narrower targeting of lead-prevention work by poverty alone.

Main findings

The analysis used the 2025 Bangladesh Multiple Indicator Cluster Survey, or MICS7. The preprint said the survey included blood-lead testing for a nationally representative group of children aged 12-59 months.

Elevated blood lead was defined as at least 5 micrograms per deciliter. That is 5 millionths of a gram of lead measured in one-tenth of a liter of blood, equivalent to 50 micrograms per liter.

The preprint reported a 95% confidence interval of 37.2% to 39.9% around the 38.5% national estimate. A confidence interval is a statistical range describing uncertainty around a sample-based estimate.

In its conclusion, the preprint said: "Lead prevention and source-identification efforts should therefore not be restricted to poor communities; prevalence remained high even in the poorest quintile." That conclusion is based on associations in a cross-sectional survey, not on proof that wealth or urban residence caused higher lead levels.

What it means

In the fully adjusted model, each higher wealth quintile was associated with 23% higher odds of elevated blood lead, with an adjusted odds ratio of 1.23 and a 95% confidence interval of 1.16 to 1.30. An adjusted odds ratio compares the likelihood of an outcome after accounting for other measured factors in the model.

Urban residence was associated with 37% higher odds, with an adjusted odds ratio of 1.37 and a 95% confidence interval of 1.18 to 1.59. Maternal education moved in the opposite direction: each higher level was linked to 20% lower odds, with an adjusted odds ratio of 0.80 and a 95% confidence interval of 0.76 to 0.84.

The preprint also found higher odds with household crowding, measured as people per room. The adjusted odds ratio was 1.17 per person per room, with a 95% confidence interval of 1.10 to 1.24.

The gap was largest in an exploratory comparison that combined wealth and maternal education. Weighted prevalence was 76.2% among children in the richest quintile whose mothers had at most primary education, compared with 19.5% among children in the poorest quintile whose mothers had higher secondary or tertiary education, a prevalence ratio of 3.9.

Limits and next steps

The preprint has not been peer reviewed, and medRxiv says such research has not been certified by peer review and should not guide clinical practice. The author also identified two important constraints: substantial missing blood lead results and coding uncertainty.

The study design also limits interpretation. Because it is cross-sectional, it measures associations at one point rather than tracing exposure over time, and it does not identify specific lead sources in homes, communities or consumer products.

Geography appeared to matter, though the preprint did not establish why. Adjusted odds relative to Barishal ranged from 0.39 in Rajshahi to 3.29 in Dhaka, indicating large regional variation after model adjustment.

The author declared no competing interests. The Institute of Health Economics at the University of Dhaka waived ethical approval for the secondary analysis of de-identified MICS7 data, which the preprint said were collected by the Bangladesh Bureau of Statistics with technical support from UNICEF.

Source: Academic preprint, medRxiv, Oct. 11, 2026