Time variations in environmental pollution

Two programmes of work are described involving the measurement of environmental pollution over periods from two hours to many years. The long period measurements are deduced from neutron activation analysis of whole wood samples taken from individual tree rings for trees grown in various locations, and some results for cadmium, antimony and germanium levels are reported. In a second series of experiments the concentration of airborne particulate matter is being measured using a moving filter (streak sampler) technique to give a continuous record with two hour resolution. The filter samples are being analysed by proton induced X-ray emission (PIXE) and preliminary data is presented.