修改一下英语表达：Moreover PFAS and photoactive species are ubiquitous in atmosphere but the retention of PFAS in atmospheric aerosols might not be completely understood based on the current bulk phase study r

Furthermore, PFAS and photoactive species are present everywhere in the atmosphere, but the retention of PFAS in atmospheric aerosols may not be fully comprehended based on current studies of the bulk phase. "Retention" means the act of keeping something or the ability to keep something in a particular place or condition.