Besides that, some element elevated on opposite side of centralized stations such as Ni at station 11 (2.09 mg/kg)
and station 12 (2.22 mg/kg). Station 12 located near power plants at Kuala Perlis that having high traffic density
from that plant. In addition, ferry transportation at station 12 also gives contribution in elevated of Ni. As reported
by A. Mandal et al., [5] heavy vehicular give large contribution through traffic emission. But Ni are mainly
originated from natural sources, thus the concentration not greatly vary from each station [7]. Thus from the overall
result, we can state that contamination level in Perlis is still in control level, just on certain location that located near
industrial areas and major road that produce high level of heavy metal. For further view on contamination level in
this study area, heavy metal assessment index will be carried out and explain further detail below.