Human exposure to lead (Pb) is a growing global public health concern. Elevated blood lead is thought to cause the mental retardation of >0.6 million children globally each year, and has recently been attributed to ~18% of all-cause mortality in the US. Due to the severe health risk, the international community, led by the United Nations Environment Programme (UNEP) and the World Health Organization (WHO), is actively supporting the global phase-out of lead-based paint by 2020. However, there are many significant hurdles on the way to achieving this goal. In light of the importance of the lead-based paint issue, and the urgency of achieving the 2020 phase-out goal, this review provides critical insights from the existing scientific literature on lead-based paint, and offers a comprehensive perspective on the overall issue. The global production and international trade of lead-based paints across Asia, Africa, Latin America, and Europe are critically discussed - revealing that lead-based paints are still widely used in many low and middle-income developing countries, and that the production and trade of lead-based paint is still wide-spread globally. In India, as well as many south-east Asian, African, Latin American and European countries, lead concentrations in paints often exceed 10,000 mg/kg. This will certainly pose a serious global threat to public health from surfaces painted with these products for many decades to come. The sources and pathways of exposure are further described to shed light on the associated health risk and socioeconomic costs. Finally, the review offers an overview of the potential intervention and abatement strategies for lead-based paints. In particular, it was found that there is a general lack of consensus on the definition of lead based paint; and, strengthening regulatory oversight, public awareness, and industry acceptance are vital in combating the global issue of lead based paint.

The adsorption characteristics and mechanisms of Ni²⁺ on four-standard biochars produced from wheat straw pellets (WSP550, WSP700) and rice husk (RH550, RH700) at 550 and 700 °C, respectively, were investigated. The kinetic results show that the adsorption of Ni²⁺ on the biochars reached an equilibrium within 5 min. The increase of the solid to liquid ratio resulted in an increase of Ni²⁺ removal percentage but a decrease of the adsorbed amount of Ni²⁺ per weight unit of biochar. The Ni²⁺ removal percentage increased with the increasing of initial solution pH values at the range of 2–4, was relatively constant at the pH range of 4–8, and significantly increased to ≥98% at pH 9 and stayed constantly at the pH range of 9–10. The calculated maximum adsorption capacities of Ni²⁺ for the biochars follow the order of WSP700 > WSP550 > RH700 > RH550. Both cation exchange capacity and pH of biochar can be a good indicator of the maximum adsorption capacity for Ni²⁺ showing a positively linear and exponential relationship, respectively. This study also suggests that a carefully controlled standardised production procedure can make it reliable to compare the adsorption capacities between different biochars and investigate the mechanisms involved.

Soil lead (Pb) pollution is wide spread in China. The Chinese government is taking ambitious actions to tackle the soil pollution issue, with the latest soil quality standards and the Soil Pollution Prevention and Remediation Law enacted in 2018. This study assesses the spatio-temporal distribution, pollution levels, major sources and health risks of Pb in surface soils in China in the past three decades (1990–2017). Traffic emissions (mainly leaded gasoline), mining, smelting, and e-waste recycling were main contributors to soil Pb pollution and pose a risk to food security and human health. The weighted arithmetic mean of Pb concentrations was 35.9 ± 0.21 mg/kg. Southern China suffered from severer soil Pb pollution with hotspots of the Pearl River Delta, Yangtze River Delta, Shaanxi and Hunan. The average soil Pb concentration increased marginally during 1990–2001 due to increased industrial and transportation activities; afterwards, it decreased by ∼30% during 2001–2013, reflecting the effectiveness of the ban on leaded gasoline in 2000. However, there was a slight increase in recent years. Therefore, it is critical to establish a comprehensive evaluation and monitoring system, strengthen pollution source control, properly manage the environmental and health risks at severely contaminated sites, and conduct green and sustainable remediation.