United States diazinon

Lawns also represent an urban ecological problem on a vast scale. In the United States, the chemicals of lawn maintenance-including dichlorophenoxy-acetic acid (2,4-D), glyphosate, diazinon, and dicamba-are significant contributors to nonpoint source water quality problems that continue to elude solution almost 30 years after the passage of the Clean Water Act. Lavm pesticides are applied on a scale to rival agricultural toxins 23% of the total 2,4-D applied in the United States is used on lawns 22% of glyphosate, 31% of chlorpyrifos, and 38% of dicamba used nationally is applied to home lavms. ... 

Estimated diazinon production in the United States for 1982 was 2.63 million kg (5.8 million pounds) (HSDB 1996). No more recent production estimates for diazinon are available. As with many toxic chemicals, especially those whose production or use involves proprietary information, quantitative estimates of production are virtually impossible to obtain (Bason and Colborn 1992). 

Official government statistics on imports and exports for chemicals such as diazinon are summarized under broad generic categories such as pesticides or organophosphates. In 1982, estimated diazinon imports to the United States were 6.41xl04kg (141,000 pounds) (HSDB 1996). No recent estimates are available on the volume of diazinon imported into the United States. Data on past and/or current import volumes are not adequate to assess trends in import volumes of this pesticide. 

Estimated diazinon use in the United States was 2.6 million pounds (1.18 million kg) of active ingredient for 1983 (Gianessi 1986) and 10 million pounds (4.5 million kg) of active ingredient for 1985 (EPA 1990b). It was estimated that up to 43% of the diazinon applied in this country in 1982 was for non-agricultural uses, 21% was used on field crops (e.g., peanuts, rice, sugarcane, small grains, and citrus),... 

Diazinon has been identified in at least 18 of the 1,430 current or former EPA National Priorities List (NPL) hazardous waste sites (HazDat 1996). However, the number of sites evaluated for diazinon is not known. The frequency of these sites within the United States can be seen in Figure 5-1. 

Although diazinon has been detected in groundwater samples in both the United States and Canada (Cohen 1986 EPA 1989a Frank et al. 1987, 1990b HazDat 1996), no studies were identified concerning diazinon transformation and degradation processes within aquifers. Based on theoretical considerations, abiotic hydrolysis mechanisms would be expected to degrade diazinon within a few months (Chapman and Cole 1982 Cowart etal. 1971). 

Since diazinon is not a priority pollutant and has not been considered to pose serious threats from bioconcentration or bioaccumulation in fish and shellfish species, it has attracted far less attention in the United States than persistent organochlorines like DDT or chlordane in routine surface water monitoring networks. Carey and Kutz (1985) reported that the maximum diazinon residue collected in a national surface water monitoring program conducted from 1976 to 1980 was 2.38 ppb and that diazinon was detected in only 1.2% of the samples collected. More recently, Pereira and Hostettler (1993) conducted a study of the Mississippi River and its tributaries during 1991 and 1992. These authors reported that... 

The National Occupational Exposure Survey (NOES) conducted by NIOSH from 1981 to 1983 estimated that 39,342 workers (including 3,216 women) employed at 3,168 facilities were potentially exposed to diazinon in the United States (NOES 1990). The NOES database does not contain information on the frequency, concentration, or duration of exposure the survey provides only estimates of workers potentially exposed to chemicals in the workplace. 

Uses Diazinon is a colorless to dark brown liquid. Based on the Toxic Release Inventory (TRI) database for 1995, approximately 107,510 pounds of production-related waste was generated by the United States. Further, releases from facilities to the environment totaled 11,498 pounds, most of which was in the form of stack emissions. Diazinon is used for the control of pest insects in soil, on ornamental plants, and on fruit and vegetable field crops. It also is used to control household pests such as flies, fleas, and cockroaches.28 42... 

Diazinon has been commonly used to control household insects such as cockroaches and ants. Household uses were eliminated in the United States in... 

Pesticides are another class of chemicals capable of damaging the nervous system and, even at low levels, produce deficits detectable by psychological testing. The organophosphorus insecticides, which are chemical relatives of the most potent nerve gases, are notorious poisons and, carelessly handled, as often happens in underdeveloped countries, can prove lethal. Parathion, diazinon, and malathion are representatives of this class and are widely used in the United States. Acute poisoning episodes produce signs such as eye irritation, headache, dizziness, nausea, and visual... 

OP insecticide-induced intermediate syndrome (IMS) was reported for the first time in human patients in Sri Lanka in 1987 (Senanayake and Karalliede, 1987). Since then, this syndrome has been diagnosed in OP-poisoned patients in South Africa (1989), Turkey (1990), Belgium (1992), the United States (1992), Venezuela (1998), France (2000), and elsewhere. IMS is usually observed in individuals who have ingested a massive dose of an OP insecticide either accidentally or in a suicide attempt. IMS is clearly a separate clinical entity from acute toxicity and delayed neuropathy. A similar syndrome has also been observed in dogs and cats poisoned maliciously or accidentally with massive dosc.s of certain OPs. OPs that are known to cause IMS include bromophos, chlorpyrifos, diazinon, dicrotophos, dimethoatc, fenthion, malathion, merphos, methamidophos, methyl parathion, monocrotophos, omethoate, parathion, phosmet, and trichlorfon. These compounds and IMS are discussed further in Chapter 26. 

Diazinon, the active ingredient in products such as Diazinon, Basudin, and Knox Out. is a nonsystemic OP insecticide. Diazinon has a half-life in soil of 2-4 weeks (Pesticide Information Profiles, 1996). In water, diazinon s half-life is related to pH, with faster breakdown related to increasing pH, whereas in neutral conditions, half-life can be as long as 6 months (Pesticide Information Profiles, 1996). Although use of diazinon on golf courses and. sod farms in the United States was banned in 1988, primarily due to its high toxicity and lethality to birds (Pesticide Information Profiles, 1996), diazinon is still widely used in Canada, although several bird deaths have been reported (Frank et ui, 1991). 

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