Coumaphos:
Health Effects
Coumaphos is an organophosphate [insecticide] which means it is a Cholinesterase Inhibitor and is highly toxic is ingested or inhaled and moderately toxic if absorbed dermally. A good summary of the acute health effects and symptoms is from EXTOXNET:
"When inhaled, the first effects are usually respiratory and may include bloody or runny nose, coughing, chest discomfort, difficult or short breath, and wheezing due to constriction or excess fluid in the bronchial tubes. Skin contact with Organophosphates may cause localized sweating and involuntary muscle contractions. Eye contact will cause pain, bleeding, tears, pupil constriction, and blurred vision. Following exposure by any route, other systemic effects may begin within a few minutes or be delayed for up to 12 hours. These may include pallor, nausea, vomiting, diarrhea, abdominal cramps, headache, dizziness, eye pain, blurred vision, constriction or dilation of the eye pupils, tears, salivation, sweating, and confusion. Severe poisoning will affect the central nervous system, producing incoordination, slurred speech, loss of reflexes, weakness, fatigue, involuntary muscle contractions, twitching, tremors of the tongue or eyelids, and eventually paralysis of the body extremities and the respiratory muscles. In severe cases there may also be involuntary defecation or urination, psychosis, irregular heart beats, unconsciousness, convulsions and coma. Death may be caused by respiratory failure or cardiac arrest."
Workers exposed to coumaphos for an extended period of time have reported impaired memory and concentration, disorientation, severe depressions, irritability, confusion, headache, speech difficulties, delayed reaction times, nightmares, sleepwalking and drowsiness or insomnia .
Coumaphos is highly toxic to birds, aquatic organisms, and a moderate hazard to other beneficial species such as bees. (EXTOXNET).
Residues: Coumaphos is a non-volatile, fat soluble substance and can migrate from wax into stored honey. Residues are a major problem for coumaphos, at least in the solution form. A number of studies have found residues in wax8; 13; 140and in samples of commercial honey44; 140. Coumaphos is the most commonly found miticide in honey in Germany140. Coumaphos was found in newly produced wax 6 months after hives were treated with Perizin23. Coumaphos added at the rate of 10ppm to beeswax foundation was present at a similar level thereafter, and increased mite mortality dramatically in the first brood cycle. Honey bee cocoons acted as a barrier for chemical transfer in subsequent brood cycles51.
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It's hard to lose colonies, but I think I'd rather risk losing my weakest bees than plough on with stronger and stronger treatments, getting more and more resistant mites and progressively weaker bees....
