As an organic dairy farmer, the late Mark Purdey of Somerset UK, resisted the order to spray his cattle with organophosphates for warble fly and went to court for a judicial review; he won and was exempted from using the spray. No cows born in his herd developed BSE (mad cow disease). Mark contributed numerous articles on the subject of BSE to scientific journals based on his "ecodetective" investigations of select regions around the world where clusters of various brain diseases have emerged. His technique of geochemical analyses of the levels of metals, radioactivity, magnetic status, etc., within the ecosystems where clusters of Alzheimer's, Parkinson's, motor neuron, multiple sclerosis and Creutzfeldt-Jacob (mad cow) diseases have emerged, enabled him to isolate various common toxic denominators which could represent the causal agents. Mark's published data and novel hypotheses indicate that the specific metal microcrystal pollutants (manganese, barium, strontium, etc.) that he observed at high levels in the cluster environments, will "seed" an aberrant growth of rogue metal-protein crystals within brain tissues; thereby initiating the pathogenesis of these diseases. He advised HRH Prince of Wales and UK government ministers, and delivered numerous lectures to universities—Harvard, Cambridge, Tokyo, Torino—across the world.