Based on these background, we have conducted a study with the following objectives.

We have attempted To elucidate the present status of contamination, according to the analysis of dioxin-related compounds in soils from dumping sites of various wastes in the Malaysia.

For this study, we collected soil samples from 4 dumping sites located in Selangor, Kedah, Penang and Kuala Lumpur on last Octorber.

These pictures show the status of dumping site in Selangor.

In this area, Municipal and industrial waste, such as vinyl sheets, plastics and other are illegally dumped. And as you can see, these waste are burned.

Few persons have worked, and domestic cows feed here.

We collected 2 sample of soils for chemical analysis.

These are in Kedah.

This dumping site were also found various wastes, including municipal and industrial wastes, and found combustion of wastes.

Similar to previous DP, domestic cows feed here, and few workers picked up usable wastes.

We collected 3 samples of soil from here.

Dumping site in Penang was terminated on 2001. There is no combustion. We collected 2 soil samples. Dumping site in KL is controlled by some company. Only municipal waste are dumped here, and no combustion is found. Two soil samples were collected and analyzed. In addition to these 4 dumping sites, we collected one samples from Lake Garden in KL for understanding background levels of dioxin-related compounds in Malaysia.

Chemical analysis of DXNs was followed the methods reported by Japan Industry Standard with some modification. Due to limited time, I would like to omit the explanation of detail.

Now, I will talk about the results and dissection .

This figure illustrates the concentration of PCDDs, PCDFs, non-ortho coplanar PCBs and mono-ortho coplanar PCBs in soils from dumping sites in Malaysia. X-axis shows the concentrations presenting pg/g on dry wt.

Dioxin-related compounds were detected from all the soil samples analyzed.

The highest concentrations of all dioxin-related compounds were found in the soil from Selangor.

For PCDD/DFs, concentrations in Kedah dumping site were second highest levels, followed by Penang, KL, and Lake Garden.
In contrast, higher levels of coplanar PCBs were found in more urban area, such as KL and Penang.

Such different order between PCDD/DFs and coplanar PCBs might be reflected the origin and sources of dioxin-related compounds.

This shows the concentration ratio of PCDD/DFs to mono-ortho coplanar PCBs. Y-axis indicates sample names and x-axis shows concentration ratio.

In general, PCDD/DFs are mainly formed during combustion of waste in dumping site, while mono-ortho coplanar PCBs are mainly originated from commercial PCB mixture.

So, high value of this ratio indicates the mass formation of PCDD and PCDFs during combustion, and lower value indicates presence of contamination by commercial PCB.

As you can see here, soils from dumping sites in Selangor and Kedah retained PCDD/DFs with higher proportions. Considering that these dumping sites were found burning of wastes, emission of PCDD/DFs during combustion in Selangor and Kedah is larger than contamination by commercial PCBs.

In contrast, lower ratio was found in soil from dumping site in Penang and KL, indicating that formation of PCDD/DFs in these area is small and contaminaiton by commercial PCBs may be significant.

This figure shows the maximum and average concentrations of PCDD/DFs in soils form Malaysian dumping site in comparison with those near emission sources in other countries.
Red bar presents the maximum concentration, and blue bar shows the mean value.

Maximum concentration of PCDD/DFs in Malaysian dumping site was the highest among the values compared here.

Mean concentration in Malaysia was lower than those in soil from dumping sites in Philippines and Greece and those from choro-alkali plants in China. However, soil from Malaysian dumping sites retained PCDD/DFs with higher levels than India, Vietnam, Japan, Spain, Netherlands and USA.

These results indicate that formation of PCDD/DFs in Malaysian dumping site are relatively great in the world.

This is the same figure for coplanar PCBs.

Due to limited information on coplanar PCB contamination in soils from developed nations, values in Malaysian dumping sites are only compared with those in Asian developing countries.

In contrast to PCDD/DFs, mean and maximum concentrations of coplanar PCBs in Malaysia were relatively low, when compared to those from Philippines, Cambodia and India. However, these were higher than those in Vietnam.

As I talked previously, contamination of coplanar PCBs is mainly originated from commercial PCBs.

Considering these, contamination levels of PCBs in Malaysia are relatively low among Asian developing countries.
This results was supported by global comparison of PCB concentrations using mussels as bioindicator species.
About the contamination levels in mussels from Malaysia, Ms. Hatijah Hashim from CAP will discuss.

Comparison of PCB concentrations in mussels from Asian countries