adrenergicbeta-antagonists adverseeffects agriculturalpollution calciumchannelblockers cardiovascularagents cc3780 chemotherapy congresses coronarydisease coronaryheartdisease dd6197 delmarvapeninsula drugtherapy effectofnitrateson environmentalaspects environmentalaspectsofnitrates environmentalhealth environmentalpollutants europeanunioncountries fertilizers foodadditives foodpreservatives groundwater health healthaspects lawandlegislation management measurement mutagenesis nitrites nitrogen nitrogenoxides nitrosocompounds nonpointsourcepollution pesticides pharmacology physiologicaleffect plants pollutants pollution qv156n278a1972 reporting standards toxicology unitedstates water waterpollution waterquality waterqualitymanagement wg300m4951992