Cautious Signs of Progress on Lead Exposure in Bangladesh

A new nationally representative survey shows that 38 percent of children in Bangladesh have elevated blood lead levels (BLLs), using 50 μg/L as a threshold—the level at which the World Health Organization recommends intervention. That’s over 20 million children who are losing IQ points, performing poorly in school, earning less as adults, more likely to be involved in crime, and have an increased risk of developing cardiovascular disease later in life. A further 7.5 percent of pregnant women were also exposed to lead, which they can pass on directly to their unborn child.

This is a whole lot of lead. But it’s a marked improvement on previous estimates. Modelling from the Institute for Health Metrics and Evaluation (IHME) shows a steady decline in average BLLs in Bangladesh since 1990, down to 70 μg/L by 2023. The new 2025 estimate from the UNICEF Multiple Indicator Cluster Survey (MICS) is 52 μg/L. This is below the trend, even for the lower confidence interval from the IHME model.

There are two possible reasons for this improvement, either a) recent policy actions have worked, or b) previous estimates were too high.

Figure 1. Bangladesh seems to be making progress against child lead exposure

Were previous estimates too high?

The previous estimates of lead exposure from IHME are modelled based on a patchwork of existing studies. The problem with most of those studies is that the samples were rarely designed to be statistically representative. Instead, they are typically focused on specific exposure hotspots, sometimes with an unexposed comparison group, selected somewhat arbitrarily from some specific locality. The mean BLL in Bangladesh from a systematic review of such small studies in 2021 was 78.7 μg/L—roughly in line with the IHME model, though comparisons are complicated because of the sampling issues.

A more straightforward comparison is for the capital region, Dhaka, where we do have an earlier representative sample, collected in 2022. Researchers from icddr;b and Stanford University found that over 75 percent of children aged two to four had a BLL above 50 μg/L. By the time of the 2025 MICS survey, this had fallen to 65 percent—more than a 10-percentage point improvement. That’s solid progress, and the apparent acceleration in response to improved policy is cause for cautious celebration. But as we wrote at the outset, that still leaves a lot of affected children. The job is far from finished.

If the improvement is real, how has Bangladesh done it?

The Bangladeshi government began prioritising lead poisoning as a national health concern in 2020, in response to growing reports of problems. There has been particular success in eliminating exposure through adulterated turmeric. Following a major government education and enforcement campaign, a study by Jenna Forsyth and collaborators found that the share of turmeric sold in markets with detectable lead fell from almost half (47 percent) in 2019, to 0 percent in 2021.

What are the other sources? The same 2022 data from Dhaka found a strong correlation with informal lead acid battery recycling. It estimated that overall around a third of exposure could be traced back to this industry, corroborating other earlier studies. Recent campaigns by youth activists have shown success in getting illegal lead smelting factories shut down.

Studies have also linked lead exposure in Bangladesh to use of pesticides and herbicides, lead solder used in food canning, indigenous medicines, and occupational exposure from recycling e-waste.

What else can we learn from the new data?

This new survey joins a handful of existing nationally representative blood lead surveys globally that give us hard data. This kind of representative data is extremely valuable both in driving action locally, and in providing some validation for global modelled IHME estimates that lean on sparse samples and extrapolation.

Second, the new data shows the geographical spread of exposure across Bangladesh, which is highly concentrated in the capital region, Dhaka. Exposure in Dhaka is twice as widespread as in the rest of the country.

Lead levels in Dhaka are twice as high as the rest of Bangladesh

Third, wealth is not a protective factor, as we’ve discussed previously. In Bangladesh, children and pregnant women from wealthier families are in fact more likely to be exposed than poorer children.

Fourth, proxy measures are not good substitutes for blood testing. The new report estimates “potential exposure to lead” based on survey responses to questions on potential environmental risk factors. This proxy measure massively underestimates actual exposure though. Just 8 percent of children are estimated to have “potential exposure to lead”—much lower than the actual measured rate of 38 percent.

Fifth, the data provides further support for the link between lead and malnutrition. This relationship works both ways. Lead competes for absorption with nutrients that our bodies need, so children with pre-existing anemia are more likely to absorb lead that they are exposed to. Conversely, children with existing lead exposure are less likely to absorb enough iron and more likely to become anemic. In Bangladesh, 44 percent of children with elevated BLLs also had anemia.

All of this is just from the preliminary report. Once the full microdata is released, we’ll be able to learn much more.

What should Bangladesh do next?

We’re optimistic that this report will spur action, just as the similar MICS survey in Georgia did. There’s a big difference between modelled global estimates from a distant American university, and real data collected by the national statistics office—in this case, the Bangladesh Bureau of Statistics. That’s a big reason to be excited about the 20 more blood lead surveys in the field around the world.

Lead exposure is preventable, and the Bangladeshi government has shown strong progress on controlling spice adulteration. The same playbook of more testing, regulatory enforcement, and public awareness campaigns, should help across a range of sources. In the meantime there are also thousands of children who need chelation treatment, and millions more who may be helped at the margin by nutritional supplements.

Bangladesh has shown that progress is possible; now it needs the same ambition for batteries, cookware, paint, and informal industry.