Inductively coupled plasma emission spectrometer(ICP-AES) and inductively coupled plasma mass spectrometer(ICP-MS) were used to determine the contents of eight heavy metals

ie.As

Cu

Cd

Cr

Hg

Ni

Pb and Zn in the soil of mangrove wetland at Zhanjiang Bay.Single factor index

Nemerow index and geoaccumulation index were used for pollution assessment.The sources of heavy metals were investigated by correlation analysis and factor analysis.The results obtained are as follows:Except for Ni

the average mass fractions for the other seven heavy metals do not exceed the national soil environmental quality standard(GB15618-2018)

but Ni

Zn

Cu

Hg

As and Cd exceed the environmental background values for Guangdong latosol

while As

Ni

Hg and Zn exceed the national environmental standard seriously.The Nemerow indexes for eight heavy metals range from 0373 to 22576

with an average of 3378

which means a serious pollution state.The single factor pollution indexes for eight heavy metals in turn are ranked as follows:Ni>Hg>Zn>Cd>As>Cu>Pb>Cr.The evaluation results of geoaccumulative indexes are consistent with those of Nemerow indexes

indicating that Hg

Zn and Ni are important factors affecting soil environmental quality in the study area.Viewing from the stations

the stations of Beiyacun and Guanhaichanglang in the north of the Bay

and Shiqiaocun in the west are serious polluted

about 33% of the total number of stations mainly attribute to Cd

Hg and Zn pollution.Statistical analysis results showed that

except for Ni

there are significant correlations among As

Cu

Cd

Cr

Hg

Pb and Zn

while the correlation between Ni and other elements is not significant.Based on the field survey results

it is inferred that the heavy metal pollutions mainly derive from the input of human activities

such as industrial pollution

ship sewage

aquaculture sewage

domestic sewage

and agricultural non-point source pollution

next from the input of natural factors.