Rodenticides toxicity

DuVall, M.D., Murphy, M.J., Ray, A.C., Reagor, J.C. (1989). Case studies on second-generation anticoagulant rodenticide toxicities in non-target species. J. Vet. Diagn. Invest. 1(1) 66-8. 

Fluoroacetic acid [144-49-OJ, FCH2COOH, is noted for its high, toxicity to animals, including humans. It is sold in the form of its sodium salt as a rodenticide and general mammalian pest control agent. The acid has mp, 33°C bp, 165°C heat of combustion, —715.8 kJ/mol( —171.08 kcal/mol) (1) enthalpy of vaporization, 83.89 kJ /mol (20.05 kcal/mol) (2). Some thermodynamic and transport properties of its aqueous solutions have been pubHshed (3), as has the molecular stmcture of the acid as deterrnined by microwave spectroscopy (4). Although first prepared in 1896 (5), its unusual toxicity was not pubhshed until 50 years later (6). The acid is the toxic constituent of a South African plant Dichapetalum i mosum better known as gifirlaar (7). At least 24 other poisonous plant species are known to contain it (8). 

Toxicity. Sodium fluoroacetate is one of the most effective all-purpose rodenticides known (18). It is highly toxic to all species of rats tested and can be used either in water solution or in bait preparations. Its absence of objectionable taste and odor and its delayed effects lead to its excellent acceptance by rodents. It is nonvolatile, chemically stable, and not toxic or irritating to the unbroken skin of workers. Rats do not appear to develop any significant tolerance to this compound from nonlethal doses. However, it is extremely dangerous to humans, to common household pets, and to farm animals, and should only be used by experienced personnel. The rodent carcasses should be collected and destroyed since they remain poisonous for a long period of time to any animal that eats them. 

Several antimicrobials have been banned or severely restricted by the EPA based on documented or suspected toxicity or environmental problems. Others have been discontinued in the face of testing costs required by the EPA reregistration program mandated by the Pederal Insecticide, Pungicide, and Rodenticide Act (PIPRA) of 1988 (10). Some of the significant products that have become obsolete are 2,4,5-trichlorophenol/P3 -5 3 -47, sodium... 

The two main federal agencies involved in the protection of human health and the environment are the Environmental Protection Agency (EPA) and the Occupational Safety and Health Administration (OSHA). EPA s principal concern is the protection of the environment, in most cases, the area outside of an industrial faciUty. There are 10 regional offices that carry out the regulatory functions of the agency (Table 1). Primary laws covered by EPA are the Clean Air Act Amendments (CAAA), the Clean Water Act (CWA), Resource Conservation and Recovery Act (RCRA), Comprehensive Environmental Response, Compensation, and LiabiUty Act (CERCLA), Toxic Substances Control Act (TSCA), and Eederal Insecticide, Eungicide, and Rodenticide Act (FIFRA). 

The United States has the most laws regarding environmental safety and health. The National Environmental PoHcy Act (NEPA) of 1969 has resulted in the following acts Eederal Insecticides, Eungicide and Rodenticide (EIERA), Resource Conservation and Recovery (RCRA), Superfund (CERCLA), Superfund Amendments and Reauthori2ation Act (SARA) Plus Tide III, Toxic Substance Control Act (TSCA), Clean Water (CWA), Water Quahty, Safe Drinking Water (SDWA), and Waste Minimi2ation and Control. 

Resource Conservation and Recovery Act Federal Insecticide, Fungicide, and Rodenticide Act Toxic Substances Control Act Nuclear Regulatory Commission Title 10... 

Another section of the EPA, the Office of Prevention, Pesticides, and Toxic Substances (OPPT), has recently updated and harmonized its testing guidelines for evaluating the developmental and reproductive effects of pesticides and industrial chemicals to include an assessment of endocrine disrupting properties. These guidelines will be used in future testing of pesticides under both the Toxic Substances Control Act (TSCA) and the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). 

The variation in toxicity of common organophosphate insecticides is exemplified in Table 5.37. The range of chlorinated hydrocarbon insecticides (Table 5.38) have, with the exception of Endrin and Isodrin, somewhat lower oral and dermal toxicities. The toxicities of a range of oilier insecticides, fungicides, herbicides and rodenticides are summarized in Table 5.39. 

Pesticides include the broad categories of insecticides, fungicides, rodenticides, and herbicides. Insecticides in common use fall into three categories. The chloroinsec-ticides have chlorine in their structure. They are less soluble than the other insecticide forms and much less biodegradable (i.e., more persistent). While they are less acutely toxic, several have been identified as potential carcinogens. Carbamatea are a relatively new form of pesticide. They are less persistent and less... 

Provides access to detailed information on all categories of pesticides including herbicides, fungicides, insecticides, and rodenticides. Included is information on pesticide toxicity, health effects, residual data, efficacy, and other information. NPIC is a cooperative effort of the U.S. EPA and the Oregon State University Department of Agricultural Chemistry. NPIC is staffed from 6 30 a.m to 4 30 p.m. Pacific Standard Time. 

Because of the delay in the appearance of hemorrhaging following exposure to warfarin and related ARs, a suitable interval must elapse between exposure of experimental animals to the chemical and the assessment of mortality in toxicity testing. Typically, this period is at least 5 days. Some values of acute oral LD50 of rodenticides to vertebrates are given in Table 11.2. 

The anticoagulant rodenticides warfarin and superwarfarins are toxic because they have high affinity for a vitamin K binding site of hepatic microsomes (Chapter 11, Section 11.2.4). In theory, an ideal biomarker would... 

Some hydroxy metabolites of coplanar PCBs, such as 4-OH and 3,3 4,5 -tet-rachlorobiphenyl, act as antagonists of thyroxin (Chapter 6, Section 6.2.4). They have high affinity for the thyroxin-binding site on transthyretin (TTR) in plasma. Toxic effects include vitamin A deficiency. Biomarker assays for this toxic mechanism include percentage of thyroxin-binding sites to which rodenticide is bound, plasma levels of thyroxin, and plasma levels of vitamin A. 

The toxicity and the physiological action of insecticides, fungicides, rodenticides, and herbicides on plants are of basic importance. The toxicity of treated plants to animals, and the toxicity of treated plants and animals to humans and to wildlife are of practical concern. A long-range consideration of the effect of sprays on both plant and human nutrition and its relation to public health is of direct concern. The hazards in field application and methods of protecting operators should be reported in detail and further research should be emphasized. 

Zinc phosphide — a rodenticide — is relatively toxic when compared to elemental zinc or zinc oxide most of the biocidal action is attributed to the phosphide fraction. Acute oral LD50s for zinc... 

Endrin was introduced in the United States in 1951 as an avicide, rodenticide and insecticide. Its principal use to control the cotton bollworm and tobacco budworm peaked in the early 1970s. In 1979, the EPA canceled some uses of endrin and indicated its intent to cancel all uses of endrin (EPA 1979f USDA 1995). By 1986, all uses were voluntarily canceled (Bishop 1984, 1985, 1986 EPA 1993e USDA 1995), except for its use as a toxicant on bird perches, which was canceled in 1991 (USDA 1995). Endrin also was a contaminant in dieldrin (Verschueren 1983) however, all uses of this pesticide have been canceled since the mid-1980s (EPA 1992b). Consequently, there are no longer any significant releases of endrin to the environment in the United States. 

Those federal regulations of interest and importance for addressing subsurface environmental issues in chronological order of establishment include the National Environmental Policy Act (NEPA), Spill Prevention, Control and Countermeasure (SPCC), the Safe Drinking Water Act (SDWA), the Resource, Conservation, and Recovery Act (RCRA), the Clean Water Act (CWA), the Toxic Substance Control Act (TSCA), the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), the Superfund Amendments and Reauthorization Act (SARA), the Federal Insecticide, Fungicide, and Rodenticide Act (FTFRA), and the Petroleum Safety Act (PSA). These regulations are discussed below. 

During our experiments on the toxicity of sodium fluoroacetate, feeding experiments were carried out on rats and its possible use as a rodenticide was recorded.3 Similar observations, not surprisingly, have been made elsewhere.4 The dangers attaching to the use of sodium fluoroacetate as a rodenticide cannot be overemphasized owing to the stability of the compound. 

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