Abstract Volatile organic compounds (VOCs) are important precursors in the formation of ground-level ozone. In this study. the hourly mixing ratios of 61 ambient VOC species were monitored from 2018 till 2019 in 10 cities in the Beijing-Tianjin-Hebei (BTH) area of China. and the VOC distributions. https://midwaysportes.shop/product-category/footballs/