A review of scientific papers has found that Bangladesh's food chain is highly exposed to lead pollution, with 100% of vegetables and 70% of fish samples showing lead contamination. The source of the lead is believed to be fossil fuel combustion, vehicle exhaust, untreated municipal sewage, fertilizer and pesticides, municipal solid waste, mining activities, and contaminated animal feed. The contamination is present in air, water, and soil, and can cause neurological growth issues in children and non-communicable diseases in adults. The economic loss due to lead-attributable IQ reduction in Bangladesh is estimated to be equivalent to 5.9% of the country’s gross domestic product.