analysis biochemicalmarkers biochemistry carcinogenesis chemistry chimie composés congresses dna dna-ligandinteractions dnadamage environmentalaspects exobiology isotopes metabolism methodology molecularevolution monitoring méthodologie nitrogen oregon organic organophosphoruscompounds phosphates phosphore phosphoruscompounds phosphorusinagriculture phosphorusradioisotopes physiologic qu130i627p1979 qu58p8571993 research sciencedesmatériaux tualatinriver waterquality