Studi in vivo pembentukan DNA adduct (8-OHDG) pada tikus (rattus novergicus) akibat bahan kimia bisphenol A (BPA) melalui reaksi fenton-like dan logam nikel (II) sebagai biomarker risiko kanker = In vivo study of DNA adduct (8-OHDG) formation of rats (rattus novergicus) by using bisphenol A (BPA) chemical through fenton like reaction and nickel (II) metal as cancer risk biomarker