sample ISO_DateTime_Local ISO_DateTime_UTC latitude longitude depth Pb_dpm Pb_stdev Bi_dpm Bi_stdev Po_dpm Po_stdev small mussel tissue a 2018-11-29T12:00:00 2018-11-29T18:00:00Z 43.01783 -87.90441 2 3 2 0 1 46 1 large mussel tissue b 2018-11-29T12:00:00 2018-11-29T18:00:00Z 43.01783 -87.90441 2 2 1 1 1 39 1