Variable
PCB_180
trans_CD
pp_DDE
pp_DDD
PCB_153
PCB_138
PCB_156
PCB_118
cis_CD
dieldrin
pp_DDT
gamma_HCH
HCB
PCB_105
PCB_101
beta_HCH
PCB_52
PCB_28
alpha_HCH
precipitation_amount
PCB_31