There's no protection against environmental pollution in China, even from latex factories. For more info: http://beijingcream.com/2012/07/wenzhou-river-runs-milky-white-after-latex-fa...
On July 9, 2012, residents near Quxi River in Wenzhou, Zhejiang province discovered the place they wash their clothes and food had turned into a "Milk River." Overnight, an emulsion leak from nearby Dashulin Trading Co. had caused serious (though non-toxic) damage.
Video source: http://v.youku.com/v_show/id_XNDI1NzI1NTI0.html