Singapore's air is now considered very "hazardous" because the allowable index of 300 has been surpassed. Pollutant Standards Index soared to 321 at last night, the worst reading in the history of the rich island nation. The last worst reading was 226 in 1997. The reason for this haze is the uncontrolled blaze on the peatlands on the outskirts of Pekanbaru in Indonesia's Riau province that started June 19. Palm oil companies are supposedly the culprits but they have denied using slash-and-burn practices on their plantations in Indonesia.