Food grown near roads or old buildings may be contaminated with lead due to historical use of leaded gasoline and lead-based paint18, 19. Food grown near, downstream, or downwind from industrial sites, landfills, and military bases may also be contaminated with various chemicals; for example, much of the U.S. mid-west is contaminated with traces of radioactive fallout from the nuclear tests in Nevada in the 1950’s20, 21. Food from the ocean, lakes, and rivers often contains trace levels of various contaminants, such as mercury and pesticides in fish22.
Since everyone consumes water each day in one form or another, drinking water can be a source of daily exposure to Prop-65 listed chemicals. Lead, arsenic, pesticides, radioactive isotopes, chlorination by-products, and other chemicals may be found at low levels in many water supplies23.
Drinking water is potentially a much more significant source of lead in the diet than a food product that contains lead above the trigger level for the Prop 65 warning.
When a food product or any other consumer product made with drinking water contains a Prop 65-listed chemical, any portion of the chemical contributed to the product by drinking water is not used to determine whether a Prop 65 warning is needed26.
18 Mielke HW, Anderson JC, Berry KJ, Mielke PW, Chaney RL, Leech M. Lead concentrations in inner-city soils as a factor in the child lead problem. Am J Public Health 1983;73(12):1366 –1369.
19 LaBelle SJ, Lindahl PC, Hinchman RR, Ruskamp J, McHugh K. Pilot study of the relationship of regional road traffic to surface–soil lead levels in Illinois. Argonne National Laboratory, Energy and Environmental Systems Division, Center for Transportation Research, Publication ANLyES-154, 1987.
20 Radioactive Fallout from Nuclear Testing at Nevada Test Site 1950 – 1960, Hearing before a Subcommittee of the Committee on Appropriations, United States Senate.
http://www.gpo.gov/fdsys/pkg/CHRG-105shrg44045/html/CHRG-105shrg44045.htm (accessed October 16, 2015)
21 Centers for Disease Control and Prevention (CDC), Radioactive Fallout from Global Weapons Testing. http://www.cdc.gov/nceh/radiation/fallout/RF-GWT_home.htm (accessed October 15, 2015)
22 Environmental Protection Agency (EPA), Studies of Fish Contamination http://www2.epa.gov/fish-tech/studies-fish-contamination (accessed October 27, 2015)
23 Environmental Protection Agency (EPA), Drinking Water contaminants http://water.epa.gov/drink/contaminants/ (accessed October 27, 2015)
24 21 CFR 165.110 Requirements for Specific Standardized Beverages – Bottled Water
25 Levin R, Schock MR, Marcus AH. Exposure to lead in U.S. drinking water. In: Proceedings of the 23rd Annual Conference on Trace Substances in Environmental Health. Cincinnati, OH, US Environmental Protection Agency, 1989.
26 Title 27, California Code of Regulations, Article 5, §25502