Theresia Sufa, Jakarta – A new study has found that more than half of schools in Jakarta are located within 5 kilometers of documented contaminated sites, potentially putting hundreds of thousands students at risk of exposure to hazardous pollutants such as lead, mercury and cadmium.
Published in June by the Center for Global Development (CGD), the study analyzed the locations of polluted sites and schools across 17 low- and middle-income countries including India, Mexico, Vietnam, Ghana, Brazil and Indonesia.
The research found that more than 250,000 schools, or 10 percent of those studied, are located within five km of contaminated sites, including battery recycling facilities, industrial areas, mining and smelting operations and waste-processing sites.
In Jakarta, 52 percent of the 7,895 schools analyzed were located within five km of contaminated sites, with nearly 370 schools within one km. The proportion was far above the national average, as about 8 percent of schools across Indonesia, roughly 31,600 schools affecting 6.5 million students, were located within five km of documented polluted areas.
The study also revealed a striking inequality pattern: private schools were more likely than public schools to be located near polluted sites. In Indonesia, schools in the wealthiest neighborhood quintile were 49 times more likely to be near documented contaminated sites than those in the poorest areas, as industrial activity and affluent communities often overlap in urban areas.
Lee Crawfurd, a senior research fellow at the CGD and lead author of the study, said lead was the most common pollutant found near schools in Jakarta.
"Lead has no safe level of exposure for children and can permanently reduce IQ and learning outcomes," Crawfurd said.
He said the findings highlight the need for Indonesia to strengthen monitoring of contaminated sites and better protect schools located near potential pollution sources.
Crawfurd recommended measures including screening sites before new schools are built, testing soil and conducting blood-lead screenings at schools near known contaminated areas, and developing a comprehensive national inventory of polluted sites.
Lead exposure is a major public health concern, particularly for children, as it can impair brain development and learning outcomes. A 2025 study by Berkhout et al. found that children exposed to lead before the age of seven and living within three km of a toxic site scored 0.48 standard deviations lower in numeracy, equivalent to roughly three years of schooling.
A 2023 study published in The Lancet Planetary Health estimated that lead exposure contributes to around 5.5 million adult cardiovascular deaths annually and is associated with the loss of 765 million IQ points among children under five worldwide. The study estimated that 90-95 percent of these impacts occur in developing countries, with the global economic cost reaching about US$6 trillion.
Budi Susilorini, Indonesia country director at environmental organization Pure Earth, a contributor to the study, said that although proximity to contaminated sites does not prove exposure, research shows a strong association between lead-contaminated environments and elevated blood lead levels in children.
"Given that there is no safe level of lead exposure, preventive measures are crucial. These include public education on the dangers and sources of lead, nationwide blood lead level surveillance, environmental monitoring, stronger enforcement of environmental regulations, setting and enforcing lead concentration standards and most importantly, eliminating lead exposure at its source," she said.
She warned that lead exposure should be treated as a major public health concern as Indonesia works toward its "Golden Indonesia 2045" vision.
"We need urgent action to protect children from lead exposure in their homes, schools and play areas. These measures must be comprehensive and integrated," she said.
Jakarta Environment Agency spokesperson Yogi Ikhwan said the study's findings provided important input for the city administration's efforts to strengthen public health protections, particularly for children, against potential exposure to heavy metals.
"For us, any information related to potential environmental and public health risks is a serious concern. We view these findings as an initial reference that requires careful, objective and data-based follow-up," Yogi told The Jakarta Post recently.
He said the agency's data showed that no lead smelting or used lead-acid battery recycling facilities were operating in Jakarta. However, the agency remained open to further investigation with researchers, ministries and relevant institutions to verify conditions in the field.
Yogi said the agency is ready to respond to any potential pollution risks through further verification, technical assessments and coordination with relevant authorities if evidence of contamination is found.