California pesticides found

Historically, attempts to demonstrate cumulative affects among harvesters or other field workers have been frought with difficulty. For Instance an analysis of data generated by a 1970 EPA survey of 822 individuals in one California county found that farm workers had lower blood cholinesterase than similar non-field Individuals, that low blood enzyme levels were associated with symptoms of headache and enteric disturbances, and that at least some individuals exhibited seasonal inhibition but no clear seasonal trend was found for the group (24). In retrospect, this latter finding is not unexpected given not only the variability in pesticide use patterns both between and within crops, but even the variability within residues of a single pesticide-crop combination (, ). 

Nakata, H. et al., Accumulation patterns of organochlorine pesticides and polychlorinated biphenyls in southern sea otters (Enhydra lutris nereis) found stranded along coastal California, USA, Environ. Pollut., 103, 45, 1998. 

A series of exploratory determinations involving air collected from four California cities was made in autumn of 1963. All but two showed measurable amounts of DDT (4). A variety of pesticides has been found in the air in several urban communities in the United States (51). 

West (12) has reviewed some of the evidences of the world-wide distribution of pesticides. Blubber from a gray whale washed up on the California shore, she reported, contained 0.2 p.p.m. of DDT, 0.5 p.p.m. of DDE, and 0.2 p.p.m. of lindane. Moreover, DDT has been found in the oil of fish caught off the coast of the Americas, Europe, and Asia in concentrations ranging from 1 to 300 p.p.m. Residues of DDT have been found in duck eggs on the Yukon River, in 75% of 2300 species of birds collected from 22 states and three provinces of Canada, and in 31 of 32 eagles examined. 

In 1969 - the year Greenpeace was founded - the federal government issued the Mrak Report (named for its senior author. Dr. Emil Mrak) which confirmed many of the dangers from pesticides described 7 years earlier by Rachel Carson. That same year the Cuyahoga River caught fire in Ohio, and a huge oil spill occurred off the coast of affluent Santa Barbara, CA, soiling the beaches of southern California. 

Table I. The seven pesticides for which residues have been found in ground water in California as a result of legal agricultural use, as of September, 1989...

Elevated risks of neural tube defects and other deformities were associated with maternal residence in proximity to agricultural pesticide applications in a California study. The risks were associated with amide, benzimidazole, methyl carbamate, or organophosphorus pesticide use. The risks were found to be greater when increasing numbers of pesticides were applied. ... 

Dichlorobenzene (DCB) in mothballs provides a different type of pesticide example. A cancer bioassay conducted by NTP (1987) found excess tumors in both rats and mice. The Intemational Agency for Research on Cancer (lARC) concluded that DCB is reasonably anticipated to be a human carcinogen, and it is listed by the State of California as a chemical known to cause cancer (see below). DCB in mothballs results in low vapor levels in areas where it is used, and vapors emanate from clothes worn after storage with DCB. An estimated human inhalation cancer risk value is available (OEHHA, 2005). Despite the widespread exposure and recognized cancer risk, there are no restrictions on the use of DCB for this purpose. 

Chemicals in lakes and streams caused 46 states to issue public health warnings to avoid or curtail the eating of fish. Mercury was the cause in 60% of the cases, polychlorinated biphenyls 22%, chlordane (a banned chlorinated insecticide) 7%, DDT 2%, the remainder being spread over 25 chemicals.182 Fish advisories went up 26% from 1995 to 1996 to the point where 15% of the lakes and 5% of the rivers in the United States are now covered.183 In fairness to industry, it should be pointed out that a study by the Lindsay Museum, in Walnut Creek, California, found that 70% of the chemicals in San Francisco Bay came from the daily activities of ordinary people (e.g., oil from leaky cars, copper dust from brake pads, garden fertilizers, and pesticides).184 Nearly 50% of the oil in the world s waters comes from people carelessly discarding used oil on the ground or down drains.185 Sixty-six percent of Delaware... 

A California groundwater survey in 1982 showed no pesticides (i.e., DBCP, EDB, carbofuran, or simazine) in the Santa Maria or Salinas Valley groundwater basins (76). DBCP was present in 6 of 23 wells in the Upper Santa Ana basin (0.1-8 ppb), and in 21 of 166 wells in the San Joaquin basin (0.1-10 ppb). The authors were unable to correlate well characteristics with DBCP concentration in water. Simazine was also found in 5 wells, carbofuran in 1 well, and EDB in 2 wells. 

Dibromochloropropane (DBCP) in California and Hawaii. DBCP has now been found in 2500 private domestic, public, and irrigation wells in California, and was recently found to have leached 400 feet downward through the unsaturated or vadose zone (44). California State Assembly Bill 1803, passed in 1984, requires the state health department to monitor 40 priority pesticides and other organics. The remaining use of DBCP on pineapples in Hawaii was cancelled (45). In a collaborative effort between EPA and USGS,... 

In 1984 the California State Water Resources Control Board (SWRCB) reported that during the past 12 years pesticide contaminants have been found In 2,893 wells (1, 2). Although 54 different pesticides have been detected In these weTls about 85% of the contamination has been caused by l,2-d1bromo-3-chloropropane (DBCP), a soil fumigant that was banned seven years ago but that Is still being detected In Increasing amounts 1n wells. 

Figure 1 shows a map of California giving the locations of the most abundantly occurring pesticides which are being found 1n groundwater. Of course, the contamination 1s not limited to agricultural chemicals such as pesticides Industrial chemicals have contributed almost equally to overall groundwater contamination, however, 1t 1s pollution by pesticides which we are concerned with here. 

While both industrial and agricultural chemicals have been found in California ground waters, pesticides injected beneath the soil surface to control nematodes are a particular concern. The nematicide 1,2-dibromo-3-chloropropane (DBCP), which was banned in California in 1977, is the most serious example of this problem in California (1-2). Figure 1 shows the increase between 1979 and 1984 in the number of wells found to contain measurable quantities of DBCP. As of April 1984, 2522 wells contained DBCP, with over half these wells (1455) having concentrations in excess of 1.0 part per billion, the current California "action level". 

Figure 9.18 Degradation of trichlopyr at 35°C in A, a California soil (0.8% organic carbon, pH 6.5) and B, an Illinois soil (4.2% organic matter, pH 5.8) giving experimental values ( ) and values calculated from the two-compartment model for the kinetic constants (day ) and the proportion found in the bound and labile compartments. [From J. W. Hamaker and C. A. I. Goring, Turnover of Pesticide Residues in Soil, in R. F. Gould, Ed., Bound and Conjugated Pesticide Residues, A. C. S. Symposium Series, No. 29, American Chemical Society, Washington, D.C., 1976, pp. 219-243.]...

The new guidelines were developed by EPA as a result of problems concerning illness among farm workers in California, particularly among those exposed to parathion in treated citrus groves. California found that Federal standards for re-entry were inadequate and imposed more stringent requirements for pesticides which inhibit cholinesterase. Other states such as Florida found less need for re-entry standards. 

Since ddt is fat soluble, it can persist in the body for a long time. The breast is 80 percent fatty tissue, and, since ddt appears to have estrogenic activity, a connection to breast cancer is conceivable. Researchers, however, have not been able to link DDT with breast cancer conclusively. In a typical study, scientists at the Kaiser Foundation Research Institute in California studied three hundred women who had undergone comprehensive physical exams in the 1960s when ddt was commonly used. Eventually, 150 developed breast cancer. Researchers had kept frozen samples of the women s blood, and, when they examined those samples and compared them with samples taken from a group of cancer-free women, they found that the pesticide residues were the same across the board. Still, concerns linger, especially since studies have linked ddt with the emasculation of alligators in Florida. 

Caution should be exercised in comparing the dermal exposure values found in these studies with other studies. These dermal exposure levels are as much as one-tenth of the amount found for other similar applications of similar pesticides outside of California. All persons were working in accord with California Worker Safety and Restricted Materials Regulations and all applications were made by trained employees of California Pest Control Operators. All of these formulations studied were California Restricted Pesticides and almost all were toxicity Category I liquids which are required to be mixed and loaded through closed systems. All workers put on clean outer clothes daily and all wore impervious gloves when contact with the concentrate was a possibility. On the other hand, caution was exercised to avoid special training, extra instructions or excessive observation because the employers and employees had been instructed to apply the pesticides in the usual manner. 

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