The damage to agricultural crops caused by ozone -- a poisonous compound commonly found in smog -- amounts to an estimated 20 billion yen every year in the Kanto region alone, Shizuoka University researchers said Saturday.
The study, conducted by Toshimasa Ohara, a professor of atmospheric environment engineering, and Kensaku Takagi, a graduate student at Shizuoka University, was released at an academic conference on atmospheric studies in Kitakyushu on Saturday.
Ozone, a blue gaseous oxygen compound most often created when automobile exhaust is exposed to sunlight, has been blamed for the death of forests in areas with high concentrations of the gas.
Ohara and Takagi studied the impact of ozone on rice, spinach and six other agricultural crops in the Tokyo metropolitan area and six prefectures in Kanto by studying crop yields and ozone density and comparing them with those grown experimentally and exposed to ozone in greenhouse settings.
They then computed the degree of damage on the basis of the unit price for those crops in each prefecture.
The most extensive damage was found in Ibaraki Prefecture, which lost an estimated 7 billion yen, followed by Chiba at 4.7 billion yen. In Gunma, damage to crops totaled an estimated 3.5 billion yen, while it came to 3.4 billion yen in Tochigi and 2.8 billion yen in Saitama.
The report says even though the yield of crops in Gunma was less than in Saitama, the greater concentration of ozone resulted in larger damage to Gunma's crops.
In terms of crops, rice suffered the heaviest damage -- an estimated 11.3 billion yen -- across the entire region, followed by lettuces at 4.3 billion yen.