Lead (Pb)

Lead (Pb) is a soft, dense heavy metal and a cumulative neurotoxin — it builds up in the body over time and causes irreversible damage, with developing children most at risk (lowered IQ, behavioural and developmental harm). There is no safe blood-lead level. It is a NAAQS criteria pollutant with an annual ambient limit of 0.50 µg/m³ and a 24-hour limit of 1.0 µg/m³.

Airborne lead comes from lead smelting and refining, lead-acid battery manufacture and recycling, the historical use of leaded petrol, and the incineration or open burning of lead-bearing waste. In recycling, the highest-risk activity is informal and formal lead-acid battery recycling, where breaking, smelting and refining lead release lead fume and dust. E-waste also carries lead — in leaded solder, CRT funnel glass and some components — released during shredding and any thermal treatment.

The exposure pathways are inhalation of lead fume and dust and ingestion of settled lead dust (hand-to-mouth), plus take-home contamination on clothing that exposes workers' families. India's history of lead poisoning clusters around informal battery-breaking units makes this one of the most serious occupational and community hazards in the recycling economy. Lead is measured in ambient air by AAS or ED-XRF on filters.

Control is strict containment: enclosed, ventilated battery-breaking and smelting; baghouse capture of lead fume and dust (which recovers valuable lead); wet methods to suppress dust; no eating or smoking in work areas; mandatory change of clothing and washing to prevent take-home exposure; and routine blood-lead monitoring of workers. Lead-acid battery recycling is tightly regulated under the Battery Waste Management Rules 2022, and unauthorised lead smelting is a frequent target of CPCB closure action.