Rain of Poison?

Reiko sent me a message just now, which I felt it wasn't right. Indeed.

From: http://news.omy.sg/News/Local%2BNews/Story/OMYStory201004231453-146217.html

简讯谣传：酸雨袭击狮城　专家：不可能

冰岛火山爆发，传本地下来这个星期会降酸雨，淋了之后会得皮肤癌，但专家驳斥这个说法，呼吁公众不需要恐慌。

本地不少公众昨天接到一则简讯，写道：“从今天到28号，避免淋到雨，因为冰岛火山爆发引起酸雨，被淋到后患皮肤癌的几率很高。”实际上，不少中国网站大肆流传了类似的消息，还指那是“750年一次的酸雨”，而且“强酸性”。

《新明日报》不少读者接到简讯后，纷纷拨电《新明日报》，询问简讯的内容是否属实，并表示担心。南大地质观察火山组的纽豪尔教授（Professor Chris Newhall）受询时直言，简讯的内容不属实，他指出，冰岛距离新加坡太远，本地受到火山爆发的影响微乎其微。“就算真的有酸雨，也是出现在欧洲地区，酸性不高。”

火山爆发10公里内才会有酸雨

纽豪尔教授解释，火山爆发后，会喷出酸性气体和硫酸气体等，造成酸雨，对生植物造成破坏，严重的话，也会影响人类健康，使人们出现咳嗽、喉咙不适等症状。　

不过，火山爆发的负面影响，只局限在10公里内，距离越远，影响就越小，因此，他认为，酸雨根本不可能侵袭新加坡。专家指出，酸雨对皮肤并没有什么影响，也不会造成皮肤癌。

I think we shouldn't underestimate the expanse of the Earth. Sure enough, we can reach Iceland by flight probably in about 10 hours. But the volcanic ashes from the eruption over there might take ages to reach here. Since the ashes diffuse in all directions, by the time they reach here the concentration would have become negligibly small, or simply zero.

If we can worry about the eruption at Iceland, I think we should worry more about eruptions closer to us at around Asia. Even volcanic eruptions from Indonesia didn't affect us much, why should we panic over one that is several times further? Besides, forest fires in Sumatra are generating much more pollution in our air instead.

Anyway rainwater is slightly acidic in nature, due to carbon dioxide and traces of acidic gases present in the atmosphere. It takes a considerable amount of acidic gas to raise the acidity of the rain significantly. This impact can only be felt within 10km radius of the eruption, according to the article. This means if Bukit Timah were to erupt, the effect of acid rain can hardly be felt in Marina Bay. However other more serious problems could arise, like the flowing lava, rain of ashes, tremors, etc.

As mentioned, the acidity of rainwater is not really that great to cause harm to our skin. Have your ever gotten skin cancer in coming in contact with carbonated drinks like coke or pepsi? Our skin isn't that fragile haha.

When a volcano erupts, there are other more pressing issues to worry about, rather than acid rain whose impact is hardly discernible.