Residues paraquat exposure

Child, 6-year-old, accidently swallowed unknown amount of Gramoxone W (contains paraquat) Residue in urine 6 days after exposure was 3.6 mg paraquat/L death 7 days after onset of symptoms. Autopsy showed ulceration of buccal mucosa, emphysema, severe lung damage, jaundice, and renal failure (Campbell 1968)... 

ELISA could potentially be used advantageously in many types of exposure and monitoring situations, for paraquat and other pesticides amenable to ELISA analysis. An obvious use of ELISA is the detection of pesticide residue levels in plant and animal tissues, or food extracts. Biological specimens such as plasma and urine currently analyzed by RIA seem particularly amenable to analysis by ELISA. Portable field kits could be developed to determine safe worker re-entry times into treated fields. Environmental samples such as soil, water, and air, can be analyzed by the ELISA. Pesticide conjugates have been proposed for skin testing of individuals suspected of sensitivity to pesticides (fi.) the ELISA could be used to detect specific antibodies in these individuals and aid in exposure studies. 

The situation is different for paraquat, which has an ADI of 0.005 mg/kg/day. Taking the 60-kg person as an example, the acceptable intake is 0.06 mg/day. On the exposure side, let us assume a residue of 0.2 mg/kg in bread and a daily consumption of 0.5 kg. This leads to an exposure of 0.1 mg/kg, which is about twice the acceptable intake. The conclusion is that, in this example, the risk associated with the residues of paraquat is not acceptable. 

Immunoassays offer much potential for rapid screening and quantitative analysis of pesticides in food and environmental samples. However, despite this potential, the field is still dominated by conventional analytical approaches based upon chromatographic and spectrometric methods. We examine some technical barriers to more widespread adoption and utilization of immunoassays, including method development time, amount of information delivered and inexplicable sources of error. Examples are provided for paraquat in relation to exposure assessment in farmworkers and food residue analyses molinate in relation to low-level detection in surface waters and bentazon in relation to specificity and sensitivity requirements built in to the immunizing antigen. A comparison of enzyme-linked immunosorbent assay (ELISA) results with those obtained from conventional methods will illustrate technical implementation barriers and suggest ways to overcome them. 

Paraquat. Paraquat is a widely used herbicide in cotton and potato culture, on orchard floors, and in landscape maintenance. There have been persistent reports of paraquat poisoning, mostly from ingestion both intentional and accidental, but also from dermal contact. There have also been reports linking paraquat to chronic intoxication, particularly in pulmonary disease from inhaling paraquat aerosols. In addition to food residue analysis in support of tolerance, worker exposure samples and ambient environmental samples are also of great interest. 

Residues on gloves and plastic boots were used as surrogates to measure herbicide transfer from treated plants. No human exposure occurred since harvesters wore protective clothing. The model was paraquat... 

The decision to use paraquat on Cannabis to control illegal marihuana production in the United States and Mexico provides another route of human exposure. This exposure results from residues accumulated at harvest, immediately after, and at subsequent times, following a spray application. This occurs when the grower attempts to salvage treated Cannabis plants after an authorized spray operation is conducted to destroy the crop. The herbicide s rapid desiccation renders the treated Cannabis unusable as a harvestable... 

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