Comprehensive Identification and Ubiquitous Occurrence of Eight Classes of Rubber-Derived Vulcanization Accelerators in Urban Dusts

Abstract

Vulcanization accelerators (VAs) serve as crucial additives in synthetic rubber on a global scale. Despite their widespread use, the environmental presence, distribution, and associated exposure risks of VAs remain poorly understood. This study compiled a target list and conducted a screening for eight classes encompassing 42 VAs in diverse urban dust samples from South China. A total of 40 of the 42 target VAs were detectable across all four studied regions, among which 30 were identified for the first time in the environment. Among the eight structureclassified VA classes, xanthates exhibited the highest concentrations (median: 3810−81,300 ng/g), followed by thiazoles, guanidines, sulfenamides, dithiocarbamates, thiurams, thioureas, and others. The median total concentrations of all target VAs (∑VAs) were determined to be 5060 ng/g in road dust, 5730 ng/g in parking lot dust, 29,200 ng/g in vehicle repair plant dust, and 84,300 ng/g in household dust, indicating the widespread presence of numerous rubber-derived VAs in various urban environments. This study marked the first systematic effort to identify a wide range of emerging rubber-derived VAs prevalent in urban environments. The findings call for increased attention to these widely utilized but less well-evaluated chemicals in future research and environmental management efforts.

Dynamics of the content of reactive oxygen species and the state of the glutathione system in the oral cavity during subchronic intoxication wuth the fungicide thiram and its antioxidant correction

“…In soil, thiram undergoes degradation with the formation of toxic dimethylcarbamosulfonic and dimethylaminothioxomethanesulfonic acids [2,3]. The presence of sulfur in the thiram molecule determines its use as a vulcanization accelerator in the production of rubber-based products; furthermore, the additives are found in urban dust and can have a negative effect on humans [4,5]. Thiram can enter the human body through the skin, respiratory tract, and orally.…”