Historical Trends of N-Cyclohexyl-2-benzothiazolamine, 2-(4-Morpholinyl)benzothiazole, and Other Anthropogenic Contaminants in the Urban Reservoir Sediment Core

Abstract

A new potential molecular marker, N-cyclohexyl-2benzothiazolamine (NCBA), was discovered in various environmental matrices (i.e., road dusts, runoff-and riverwater particles, river sediments, aerosols) taken in Tokyo, Japan. Concurrent determination of this compound together with 2-(4-morpholinyl)benzothiazole (24MoBT), previously proposed marker of road dust, demonstrated that both compounds are widely distributed in the urban environment (∼ng/g to ∼µg/g), derived from vehicle tire tread, and transported in the environments in the same way. To assess utilities of NCBA and 24MoBT as molecular markers for vehicle-derived contaminants, these compounds were analyzed in a sediment core from the Chidorigafuchi Moat of Imperial Palace, situated in the center of Tokyo. Remarkable is that NCBA existed at higher concentrations than 24MoBT near the surface (0-6 cm depth) and bottom parts (16-24 cm depth) of the region where BTs were detected but lower in the middle parts (6-16 cm depth). Dating of the core by using 137 Cs and tetrapropylenebased alkylbenzenes (TABs) revealed the two changeovers coincide well with changes in the production history of vulcanization accelerators containing the compounds. The dated downcore profile of ∑BTs (sum of 24MoBT and NCBA) showed positive correlation with the traffic data in Tokyo Metropolitan Area. These results indicate the usefulness of NCBA and 24MoBT as time markers for recent sections of sediment cores and as molecular markers for reconstructing the history of traffic-induced contamination.

Distribution behavior of polycyclic aromatic hydrocarbons in roadside soil at traffic intercepts within developing cities

“…The impact of automobile emissions on environment, predominantly on soil, air and water is increasing day by day. Automobile emissions have shown a tremendous impact on the environment during the past few years (Kumata et al, 2000). One of the toxic contaminants found in roadside soil and dust includes PAHs.…”

Occurrence, Sources, and Fate of Benzothiazoles in Municipal Wastewater Treatment Plants

“…However, the initially applied parent compounds such as TCMTB or MoTBT were not detected, as these undergo quick transformation (6,10). Instead, putative transformation products such as BT and MTBT (5,7,(11)(12)(13) or stable byproducts such as 2-(4-morpholinyl)-benzothiazole or N-cyclohexyl-2-benzothiazole (14) were detected. These detections were often only qualitative or semiquantitative and most studies on the occurrence of benzothiazoles in wastewater or surface water were limited to isolated samples.…”

Polycyclic aromatic hydrocarbons (PAHs): contamination level and risk assessment in urban areas, Kuala Lumpur, Malaysia

“…Previous studies have reported that the origin of PAHs in road dust were mainly from automobile exhaust [14,20], road pavement material or asphalt [14,21], tire rubber, and lubricant oil [21]. Similar to aerosols, road dust will be deposited onto the surface water by rain [22,23] bringing along the PAHs into the water reservoirs. The concentrations of PAHs in road dust vary with the distance of its sources [24].…”