Editing Lead (section)

== Environmental effects ==
[[File:Batteries at Thiaroye.jpg|thumb|left|Battery collection site in [[Dakar]], Senegal, where at least 18 children died of lead poisoning in 2008|alt=A dusty dump]]

The extraction, production, use, and disposal of lead and its products have caused significant contamination of the Earth's soils and waters. Atmospheric emissions of lead were at their peak during the Industrial Revolution, and the leaded gasoline period in the second half of the twentieth century.{{sfn|United Nations Environment Programme|2010|p=4}}

Lead releases originate from natural sources (i.e., concentration of the naturally occurring lead), industrial production, incineration and recycling, and mobilization of previously buried lead.{{sfn|United Nations Environment Programme|2010|p=4}}  In particular, as lead has been phased out from other uses, in the Global South, lead recycling operations designed to extract cheap lead used for global manufacturing have become a well documented source of exposure.{{sfn|Renfrew|2019|p=8}} Elevated concentrations of lead persist in soils and sediments in post-industrial and urban areas; industrial emissions, including those arising from coal burning,{{sfn|Trace element emission|2012}} continue in many parts of the world, particularly in the developing countries.{{sfn|United Nations Environment Programme|2010|p=6}}

Lead can accumulate in soils, especially those with a high organic content, where it remains for hundreds to thousands of years. Environmental lead can compete with other metals found in and on plant surfaces potentially inhibiting [[photosynthesis]] and at high enough concentrations, negatively affecting plant growth and survival. Contamination of soils and plants can allow lead to ascend the food chain affecting microorganisms and animals. In animals, lead exhibits toxicity in many organs, damaging the nervous, [[kidney|renal]], reproductive, [[Haematopoiesis|hematopoietic]], and cardiovascular systems after ingestion, inhalation, or skin absorption.{{sfn|Assi|Hezmee|Haron|Sabri|2016}} Fish uptake lead from both water and sediment;{{sfn|World Health Organization|1995}} bioaccumulation in the food chain poses a hazard to fish, birds, and sea mammals.{{sfn|UK Marine SACs Project|1999}}

Anthropogenic lead includes lead from [[Shot (pellet)|shot]] and [[Fishing sinker|sinkers]]. These are among the most potent sources of lead contamination along with lead production sites.{{sfn|United Nations Environment Programme|2010|p=9}} Lead was banned for shot and sinkers in the United States in 2017,{{sfn|McCoy|2017}} although that ban was only effective for a month,{{sfn|Cama|2017}} and a similar ban is being considered in the European Union.{{sfn|Layton|2017}}

Analytical methods for the determination of lead in the environment include [[spectrophotometry]], [[X-ray fluorescence]], [[atomic spectroscopy]], and [[electrochemistry|electrochemical methods]]. A specific [[ion-selective electrode]] has been developed based on the ionophore ''S'',''S'''-methylenebis(''N'',''N''-diisobutyl[[dithiocarbamate]]).{{sfn|Hauser|2017|pp=49–60}} An important biomarker assay for lead poisoning is [[δ-aminolevulinic acid]] levels in plasma, serum, and urine.{{sfn|Lauwerys|Hoet|2001|pp=115, 116–117}}