Calculations and References on Acceptable Lead Levels


The first assumption is that electric vehicles reduce carbon emissions.  For this simple analysis, the assumption is that emissions from an EV will be zero.  EV adoption rate found by others will be used to estimate the increase in metals mining required to support the shift to low-carbon transporation.  Looking at the current EV growth rate, an amount of metals per CO2 reduction will be estimated.  The lead emissions resulting from the mining, smelting and purification of those metals will then be applied as an estimate of "acceptable" lead emissions per CO2 reduction. 

This is clearly a false equivalency and the data is spotty.  I can find good estimates linking increased copper use in EVs and for lead emissions in copper mining.  Other materials, like aluminum, cobalt, nickel, manganese and lithium will clearly be needed in greater quantities for EVs, but I don't have good data on increased use and mining lead emisisons.  Since copper is the major increase, this will serve as a lower bound estimate. 

Increased copper is represented in a dataset attributed to Reuters.  It is also reflected in data from Real Clear Energy.  The prediction is that copper demand for the EV sector is projected to rise from less than 500,000 tons today to nearly 1.5 million tons in 2025, and to 3.3 million tons in 2030.  That is a delta of 2.8 million tons of copper.

EV prevalence in 2030 is from IEA.  7.5% of all cars will be EVs in 2030.

USGS data provides global copper production.  USGS give 20 million tons of total copper mined in 2020.

The lead emissions from copper are mainly from EPA report EPA-454/R-98-006, "Locating and Estimating Air Emissions From Sources of Lead and Lead Compounds".   Summing emissions given in the report gives 0.171 g lead emissions/kg of concentrated ore processed.  Concentrated ore is between 25 and 30% Cu.  For the calculation, 27% will be used.

Fuel use data from 2021 BP Statistical Review found at 

Global gasoline in 2020 is on page 27 and is reported as 21,325  thousang barrels per day. 
Conversion factor from page 68 of 0.12 tons per barrel and assuming a 365 day year gives 934035000 tons per year.  Further, global gasoline relatively flat over the last 5 years.  The assumption is today's use is 2030 use minus what EVs would use.

Emissions from passenger cars comes from EIA.  Page 298 of the 2021 World Energy Outlook give 3.003 million tons of CO2.  As a check, multiplying the gasoline consumption reported by BP by 44/14 to convert moles of CO2 to moles of -CH2- also gives 3 million tons. 


CO2 reduction will be 7.5% (from the fraction of EVs in 2030) of the projected emisisions, estimated as 3 million tons.  That gives 225 million tons CO2 reduced by EVs. 

Lead emissons attributable to EVs will be estimated from only the Cu.  The amount of copper added due to EVs is 2.8 billion kg.  At 27% Cu in concentrate, that implies 10.4 billion kg of ore.  Applying the  0.171 g lead emissions/kg of concentrated ore processed gives 1773 tons of lead emissions associated only with the added copper used in EVs. 

Now I have an estimate of the emission factor.  7.87 g emitted lead per ton of avoided CO2 emissions due to EVs projected in service in 2030.

Now, for the thought experiment.  I assume that 7.87 g emitted lead per ton of avoided CO2 emissions is and "acceptable" level.  I am going to propose a newly discovered additive that, when added to gasoline, doubles the mileage.  It also contains lead.  The maximum lead allowed is the "acceptable" level emitted in EV production. 

Reducing emissions by half is 1.5 billion tons.  That implies "acceptable" lead of 11,800 tons of lead in the gasoline pool.  That is between 40 and 80 ppm,  or between 1/40 or 1/80 the part per thousand in leaded gasoline.  The 1/80th assumes that emissions will be cut while gasoline use remains constant.  The 1/40th assumes the mythical additive doubles engine performance, as TEL did back in the 1920s.  The mythical additive essentially cuts emissions by cutting overall fuel use.

This is an estimate fraught with peril and represents somewhat of a lower bound since I've only looked at copper.  It does point out that zero lead is not really a possibility.  The move from a fuel-centric to materials-centric transportation system will surely come with lead. 

General Lead Pollution References:

Really good article but a little old.  Pacyna, J.M. and Pacyna, E.G., 2001. An assessment of global and regional emissions of trace metals to the atmosphere from anthropogenic sources worldwide. Environmental reviews, 9(4), pp.269-298.

USGS Understanding Contaminants Associated with Mineral Deposits

Occupational Knowledge International>

Meteorological Synthesizing Centre - East (MSC-E)-one of the international research Centres of the EMEP programme


last updated 16 November 2021