According to Ladd, perchlorate exists in the lower Colorado River at a level of 5 to 10 parts-per-billion, and likely concentrates in some irrigated food crops by several orders of magnitude during the hot desert summer. Ladd has found that a few years ago NASA's Florida operations had requested permission to dispose of old ammonium perchlorate rocket fuel by dispensing it as free fertilizer, but eventually decided against the project.

Ladd has found that there are some indications that NASA's plan merely reflected what was once a common, informal practice in the aerospace industry. Perchlorate is known to have been distributed to manufacturers in 44 states. A water survey by the Suffolk County Public Health Department on New York's Long Island estimated that just under 10% of the county's wells contained levels of perchlorate comparable to those found in the Colorado River, and Suffolk County health officials suspect that their perchlorate came from contaminated nitrate fertilizer. Aerospace scientists claim they have found perchlorate in commercial fertilizer purchased in Georgia, and EPA researchers have verified that a nitrate deposit in the Chilean desert that supplies fertilizer for farmers around the world contains .4% perchlorate.

Defense industry-financed research is underway at Harvard to determine how readily perchlorate concentrates in the human thyroid. The conventional wisdom is that perchlorate's ability to lower thyroid hormone levels is solely based on passive blockage of iodide uptake, and that perchlorate levels found so far in drinking water do not present a health hazard. Concentrations of perchlorate in some food, however, are likely to be substantially higher than levels found so far in the nation's water supply. In addition, no research has been funded to establish with absolute certainty that perchlorate does not react inside the thyroid.

Take Action!!

As of June 14, 1999 the EPA closed the public comment period for its decision to not test the nation's drinking water for perchlorate. However, past experience indicates that public outcry can alter EPA administrative decisions, so persons concerned about perchlorate in their water supply should email the EPA at ow-docket@epamail.epa.gov. Messages should request that perchlorate be subject to "unregulated contaminant monitoring in public water systems" and referenced as follows: "Re: Docket W-98-02 , Perchlorate and the UCM list."