Persistence of organochlorine insecticides on different substrates under different environmental conditions. I. The rates of loss of dieldrin and aldrin by volatilisation from glass surfaces

The losses of dieldrin and aldrin by volatilisation from crystalline deposits on glass surfaces in different environments were studied by using these insecticides labelled with the radioactive isotope 36 CL as a tracer. Volatilisation rates were very sensitive to changes in temperature and to a lesser extent to air movement, but not to change in relative humidity (the effect of which was measurable only on porous glass surfaces). All rates of loss from glass surfaces could be described mathematically in terms of single or double exponential equations, although many were better described by simple sigmoid (logistic) equations.