As late as 2002, almost all low- and middle-income countries including some OECD members still used it. The  UN Environment Programme (UNEP) thus launched a campaign in 2002 to eliminate its use, leading to Algeria being the last country to stop its use in July 2021. Lead-containing products
Lead can be found in products such as kohl, an ancient cosmetic from the Middle East, South Asia, and parts of Africa that has many other names; and from some toys. In 2007, millions of toys made in China were recalled from multiple countries owing to safety hazards including lead paint. Vinyl mini-blinds, found especially in older housing, may contain lead. Lead is commonly incorporated into herbal remedies such as Indian Ayurvedic preparations and remedies of Chinese origin. There are also risks of elevated blood lead levels caused by folk remedies like azarcon and greta, which each contain about 95% lead.Ingestion of metallic lead, such as small lead fishing lures, increases blood lead levels and can be fatal. Ingestion of lead-contaminated food is also a threat. Ceramic glaze often contains lead, and dishes that have been improperly fired can leach the metal into food, potentially causing severe poisoning. In some places, the solder in cans used for food contains lead. When manufacturing medical instruments and hardware, solder containing lead may be present. People who eat animals hunted with lead bullets may be at risk for lead exposure.
Nasu–Hakola disease also known as polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy is a rare disease characterised by early-onset dementia and multifocal bone cysts. It is caused by autosomal recessive loss of function mutations in either the TREM2 or TYROBP gene that are found most frequently in the Finnish and Japanese populations. Signs and symptoms
Four stages are recognised in this condition. The first (latent stage) show no symptoms or signs. This stage typically lasts up to the early 20s. This is followed by the osseous stage. This is characterised by recurrent bone pain usually affecting the long bones of the limbs. This is usually followed by pathological fractures of these bones. The third stage (early neurological) is marked by the onset of symptoms typical of a frontal lobe syndrome (euphoria, lack of concentration, loss of judgment and social inhibitions) with memory loss. Epilepsy may occur. This stage usually has its onset in the late 20s and early 30s. The final stage is characterised by severe dementia and paralysis. Death usually occurs in the late 40s or early 50s. Genetics
This condition has been associated with mutations in the TYRO protein tyrosine kinase binding protein (TYROBP) gene and in the triggering receptor expressed on myeloid cells 2 (TREM2) gene. TYROBP is located on the long arm of chromosome 19 (19q13.12) and TREM2 is located on short arm of chromosome 6 (6p21.1). Pathopysiology
This is not understood but appears to involve the microglia. Diagnosis
This syndrome may be suspected on clinical grounds.