Mutagenic Activity of Surface Soil and Quantification of 1,3-, 1,6-, and 1,8-Dinitropyrene Isomers in Soil in Japan

Abstract

To clarify the mutagenic potential of nonagricultural surface soil in Japan, 110 soil samples were collected from five geographically different areas between November 1996 and March 1997, and organic extracts of the soil samples were examined by the Ames/Salmonella assay. Most of the soil extracts showed mutagenicity toward both strains TA98 and TA100 in the presence and/or absence of a mammalian metabolic activation system (S9 mix), suggesting that surface soil is largely contaminated with environmental mutagens. Soil samples collected at Hekinan, Kobe, and Osaka were highly mutagenic toward both strains, and their potencies toward TA98 without S9 mix were extremely high, inducing more than 12 000 revertants per gram of soil. On the other hand, soil samples from Muroran showed strong mutagenicity toward TA100 with S9 mix. Furthermore, 1, 3-dinitropyrene (DNP), 1,6-DNP, and 1,8-DNP in soil samples collected at 10 sampling sites in three metropolitan areas were quantified by fluorometric detection of the corresponding diaminopyrene isomers using high-performance liquid chromatography (HPLC). Three DNP isomers were detected in all soil samples, and the amounts of 1,3-, 1,6-, and 1,8-DNP isomers in the soil samples were 12-3270, 14-5587, and 13-6809 pg/g, respectively. The gross amount of three DNP isomers in surface soil collected at Hekinan was more than 10 ng per gram of soil. The highest contribution ratios of DNP isomers to the mutagenicity of soil extracts were observed for the samples collected at Osaka, and the total of the contribution ratios of three DNP isomers was about 50%. These results suggest that surface soil is largely contaminated with mutagenic compounds and that DNP isomers are one class of major mutagenic and carcinogenic compounds contaminating surface soil.

Polar Compounds Dominate in Vitro Effects of Sediment Extracts

“…Nitro-and dinitro-PAHs such as 1-nitropyrene and 1,3-and 1,8-dinitropyrene detected in F13 and F14 were found to be potent direct and indirect acting mutagens in Salmonella typhimurium. 22,23 Furthermore, methylparathion, aminoanthraquinone, and dibenzoacridines detected in F14, F15, and F17, respectively, have been reported to be Figure 1. Mutagenic responses of total (par), reconstituted (rec), and fractionated (1-18) P relou c (P), Most (M) and Bitterfeld (B) sediment extracts determined with tester strain TA98 without (horizontally shaded) and with (white) metabolic activation, and with TA100 without (diagonally shaded) and with (black) metabolic activation by S9.…”

Mutagenicity of Surface Soils in Urban Areas of Aichi Prefecture, Japan, and Bangkok, Thailand

“…In a previous study, 8) we examined the mutagenicity of 110 surface soil samples collected from five geographically different regions of Japan, i.e., the To clarify the contamination levels of surface soil with mutagens in urban areas of Aichi prefecture, Japan, and Bangkok, Thailand, 60 and 67 surface soil samples were collected in Aichi and Bangkok, respectively, and mutagenicities of the organic extracts from these soil samples were examined in the Ames assay using Salmonella typhimurium (S. typhimurium) TA98 and TA100 with and without a mammalian metabolic system (S9 mix). Most of the soil samples collected in both areas showed mutagenicity in TA98 with and without S9 mix and in TA100 with S9 mix.…”

“…Collection and Preparation of Organic Extracts from Surface Soil ---Sample collection and preparation of organic extracts were carried out by the methods described previously. 8) Soil samples were collected at parks or roadsides in two areas in Aichi prefecture, i.e., Nagoya and Hekinan and adjacent areas, and in Bangkok and its adjacent provinces between February 2000 and March 2001. Sampling was carried out after a minimum of 7 days of nonrainy weather.…”

“…Many researchers have reported that organic extracts from surface soil showed mutagenic and DNA-damaging activity. [5][6][7][8][9][10][11] To examine the hypothesis that automobile exhaust contributes to soil mutagenicity, Wesp et al 7) exposed two soils with low levels of mutagenic activities to traffic exhaust at a junction with heavy traffic for 3-26 weeks and found that mutagenic activities of the soils were increased at rates of 4-12 revertants per gram of soil per week in the Ames assay using Salmonella typhimurium (S. typhimurium) TA98 and TA100.…”

“…Furthermore, it was found that some soil samples, e.g., one from Hekinan in Aichi prefecture, showed remarkably high mutagenicity, and three dinitropyrene (DNP) isomers, i.e., 1,3-, 1,6-, and 1,8-DNP, were detected in soil samples from Hekinan. 8) Hekinan is a constituent city of the Chukyo industrial region, one of the largest industrial regions of Japan in which heavy industries such as metal smelting and the chemical industries are found. Because DNP isomers are representative airborne mutagens and carcinogens formed by incomplete combustion of organic materials such as fossil fuels, 12,13) the soil pollution in Hekinan might be caused by industrial activity such as the combustion of fossil fuels in factories and by motor vehicles used to transport raw materials and products.…”