Lead cycle

Simplified schematic of the lead cycle. All values indicated are fluxes with unit of Mg/yr; the values have been obtained from Cullen and McAlister (2017).[1] The size of the arrows are approximately proportional to their flux. The major reservoir for lead is the crust and mantle with a concentration of 11–14.8 ppm.[1] The natural sources (green arrows) of lead in the atmosphere are volcanic eruptions, plant exudates, forest fires, extraterrestrial particles, radioactive decay, and physical and chemical weathering of rocks.[2] The major anthropogenic sources (red arrows) are mining and smelting of ores, non-ferrous metal production, stationary fossil fuel combustion platforms, and mobile fossil fuel combustion platforms.[1] The sinks (blue arrows) of lead are wet deposition of aerosols on to the ocean water surface[3] and the subsequent burial in deep sediments. Since lead is toxic to life, there are no predominant metabolic pathways.[1]

The lead cycle is the biogeochemical cycle of lead through the atmosphere, lithosphere, biosphere, and hydrosphere, which has been influenced by anthropogenic activities.

  1. ^ a b c d Cullen, Jay T.; McAlister, Jason (2017). 2. Biogeochemistry of Lead. Its Release to the Environment and Chemical Speciation. Vol. 17. De Gruyter. doi:10.1515/9783110434330-002. ISBN 978-3-11-043433-0. PMID 28731295. {{cite book}}: |journal= ignored (help)
  2. ^ Pacyna, J. M.; Pacyna, E. G. (2011). "An assessment of global and regional emissions of trace metals to the atmosphere from anthropogenic sources worldwide". Environmental Reviews. 9 (4): 269–298. doi:10.1139/a01-012.
  3. ^ Boyle, Edward; Lee, Jong-Mi; Echegoyen, Yolanda; Noble, Abigail; Moos, Simone; Carrasco, Gonzalo; Zhao, Ning; Kayser, Richard; Zhang, Jing; Gamo, Toshitaka; Obata, Hajime (2014). "Anthropogenic Lead Emissions in the Ocean: The Evolving Global Experiment". Oceanography. 27 (1): 69–75. doi:10.5670/oceanog.2014.10. hdl:1721.1/87593. ISSN 1042-8275. S2CID 129503230.