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The global increase in electronic waste (e-waste) has led to a rise in informal recycling, emitting hazardous heavy metals (HMs) that threaten human health and ecosystems. This study presents the first comprehensive assessment of HM levels in dry deposition and soils at proximity of forty (40) informal e-waste recycling sites across Pakistan, between September 2020 to December 2021. Findings reveal that Zn (1410), Pb (410) and Mn (231) exhibited the higher mean deposition fluxes (μg/m2.day), derived from air samples, particularly in Karachi. Similarly, soils showed higher mean concentrations (μg/g dw) of Mn (477), Cu (514) and Pb (172) in Faisalabad, Lahore, and Karachi, respectively. HMs concentrations were found higher in winter or autumn and lower in summer. In addition, HM levels were significantly (p = 0.05) higher at recycling sites compared to background sites year-round, highlighting the e-waste recycling operations as the major source of their emissions. The I geo index indicated moderate to extremely contaminated levels of Cu, Pb, Cd, and Ni in Karachi, Lahore and Gujranwala. Ingestion was found as a leading human exposure route, followed by dermal and inhalation exposure, with Pb posing the greatest health risk. The Cumulative Incremental Lifetime Cancer Risk (ILCR) model suggested moderate to low cancer risks for workers. Strategic interventions recommend mitigating health and environmental risks, prioritizing human health and ecosystem integrity in Pakistan's e-waste management. [Display omitted] • Informal e-waste recycling in Pakistan emits Zn, Mn, Pb, harming health/ecosystems. • Heavy metal concentration in air and soil for Karachi were the highest and warrant further attention. • Heavy metals in air exhibited seasonality and peaked in autumn/winter. • High human exposure estimates for Pb highlight the need for improved e-waste management in Pakistan. [ABSTRACT FROM AUTHOR]

[Display omitted] • Measurement of GEM emissions from urban atmosphere in Pakistan. • Open burning, and physical dismantling are common e-waste recycling practices. • E-waste sites from Karachi, Lahore, and Peshawar were found highly contaminated. • Lower seasonal variations indicating the stable emission sources throughout year. • Workers and public living close to these facilities are exposed to hazards of GEM. Detrimental effects of mercury (Hg) on ecosystems and human health have been well-documented. Whereas emissions of gaseous elemental mercury (GEM) from e-waste recycling have been reported in developed countries, much less is known about the situation in the Global South. Using a total of 132 passive air samplers, seasonally resolved concentrations of GEM in air were measured continuously at 32 informal e-waste recycling facilities and background location in Pakistan for a period of one year between September 2020 and December 2021. Annual average GEM concentrations at the studied locations ranged from 1.8 to 92 ng m−3. Among the studied cities, higher concentrations were measured in Karachi (mean ± s.d: 17 ± 22, range: 4.2–92 ng m−3), Lahore (16 ± 4.2, 8.2–22 ng m−3) and Peshawar (15 ± 17, 4.9–80 ng m−3), while lower levels were measured in Hyderabad (6.9 ± 6.2, 3.1–25 ng m−3), consistent with a higher rate of informal recycling activities in metropolitan areas. Seasonally, higher GEM levels occurred during autumn (15 ± 16: 3.3–92 ng m−3) and summer (13 ± 8.7: 1.8–80 ng m−3) than in winter (12 ± 8.4: 2.5–49 ng m−3) and spring (9.2 ± 7.3: 1.8–80 ng m−3), possibly reflecting enhanced volatilization at higher temperatures and/or varying magnitude of recycling operations in different seasons. Policies and strict regulations related to e-waste management should be developed and implemented urgently in the country. [ABSTRACT FROM AUTHOR]