International Lead Poisoning Prevention Week (ILPPW) takes place every year during the 3rd week of October. WHO identifies lead as one of 10 chemicals of major public health concern needing action by Member States to protect the health of workers, children, and women of reproductive age. The focus of this year’s campaign “End Childhood Lead Poisoning” aims to remind governments, civil society organizations, health partners, industry, and others of the unacceptable risks of lead exposure and the need for action to protect children's health.
Lead is a toxic metal of public health concern that affects multiple body systems, including the neurological, haematological, gastrointestinal, cardiovascular, renal immune, endocrine and reproductive systems. World Health Organization’s (WHO) latest estimates suggest that nearly half of the 2 million lives lost to known chemicals exposure in 2019 were due to exposure to lead. Additionally, lead exposure was estimated to account for 21.7 million years lost to disability (disability-adjusted life years, or DALYs) worldwide in 2019, including 30% of the global burden of idiopathic intellectual disability, 4.6% of the global burden of cardiovascular diseases and 3.0% of the global burden of chronic kidney diseases. Chronic exposure to lead is one of the causes of anemia in children and also leads to delayed growth and stunting.
Lead is widely present in the environment. Exposure to lead occurs through environmental and occupational sources leading to contamination of dust or soil, as well as through cosmetics, food and spices, flakes of lead paint, toys, batteries and lead-containing traditional medicines. Drinking water can become contaminated using lead galvanized pipes, hand pumps, or wash-off from lead-contaminated soil and surfaces. Exterior paint may also be removed by weather conditions and find its way through stormwater and surface water run-offs, especially in urban settings.
Children experience far greater effects from lead, as they can absorb lead 4-5 times more than adults and are at greater risk of exposure due to their age-related behaviour through swallowing or ingesting lead-contaminated objects, soil, or paint scrapings. The most notable pathways of children's exposure to lead are associated with toys, deteriorated paint chips at home and around playground equipment, or contaminated soil.
There are no safe levels of lead. It is absorbed through the digestive tract, is stored in teeth and bones, and is continuously released into the bloodstream. Blood concentrations as low as 3.5µg/dL have been associated with decreased intelligence in children(WHO 2021). UNICEF assessment in 2020 estimated that almost one in three children globally may have experienced blood levels of 5µg/dl or more at some point in their development.
In Sri Lanka, the true impact of lead among children is not fully understood however as in other parts of the world, children in Sri Lanka also continue to be at risk of exposure to lead through paint dust and scrapings, handling of toys, electronics scrap, and lead-glazed food containers.
Sri Lanka has taken regulatory measures to restrict exposure to lead since 2013. The regulations on paint products restrict lead concentration to a maximum of 600 parts per million (ppm), and to 90mg/kg for paints used for toys and accessories for children. Lead measurement is included in national drinking water quality standards. The Sri Lankan standard for lead in drinking water is 10 μg/l (Sri Lankan Standard Institute 2013), which is in line with the WHO provisional guideline for lead in drinking water (WHO 2011). An environmental protection licensing system has been introduced by the Central Environmental Authority for emission or disposal of waste items which includes lead, such as batteries and electronic equipment (2008).
Despite regulations in place, addressing lead pollution and minimizing its exposure remain a challenge. Assessment of paints, toys, and playgrounds from across the world have continued to show the presence of lead concentrations in dust or paints much higher than stipulated under regulations. Therefore, measures of monitoring compliance with regulations are recommended such as mandating the labeling of the content of lead on all paints, as well periodic verifications through laboratory testing. Additionally, minimizing the risk of lead pollution and exposure among children through other measures is important.
Primary prevention (i.e., the elimination of exposure to lead at its source) is the single most effective intervention against lead poisoning. As the risk of lead contamination in the environment remains high through a variety of sources, it is crucial to continue monitoring the environment and mitigate the risk of contamination to protect the health of children. The governments are suggested to consider monitoring the use of lead paints in homes, schools, school materials and children’s toys. The deteriorated paint chips from playground equipment are an important pollutant and should be removed effectively.
To prevent contamination of lead in water, the use of galvanized plumbing and fittings is discouraged, as well water sources should be regularly monitored, especially in areas prone to catchments with lead contamination. The provisional guideline value for lead in WHO Guidelines for drinking water has been 10µg/dl, although it does not constitute an emergency unless the concentrations are continuously found to be very high. Therefore, continuous monitoring through national drinking-water quality surveillance is encouraged. Governments are also encouraged to eliminate the use of lead glazing for pottery intended for cooking, eating, or drinking.
To mitigate the risks further, public awareness about the dangers and sources of lead exposure is important, especially among individuals associated with industries using lead, and in the construction sector. The recycling of lead-containing waste (e.g., lead acid batteries, electronic scrap) should be considered through appropriate industrial hygiene measures, and informal recycling and use of lead-containing waste should be discouraged.
To continue advocacy efforts towards reducing exposure to lead, WHO Sri Lanka along with the Ministries of Health and Environment plans to include information about dangers and sources of lead exposure in public health messaging targeted to parents, schools, care givers, youth associations and community groups . WHO will also support primary health care sector awareness and develop guidance to identify, manage and treat lead exposure among children or pregnant mothers suspected with lead exposure.