这组科学家通过分析2002年在伊洛瓦底江三角洲进行的地下水测试从而证实了他们的发现，而且去年还在南苏门答腊省采集了地下水样本。
The researchers confirmed their findings by analysing groundwater tests conducted in the Irrawaddy delta in2002 , and collecting groundwater samples in the province of southern Sumatra last year .
南苏门答腊省