Surgical masks have been worn by the public worldwide during the COVID-19 pandemic, yet hazardous chemicals in the petroleum-derived polymer layer of masks are currently ignored and unregulated. These organic compounds pose potential health risks to the mask wearer through dermal contact or inhalation. Here, we show that surgical masks from around the world are loaded with semivolatile and volatile organic compounds (VOCs), including alkanes, polycyclic aromatic hydrocarbons (PAHs), phthalate esters, and reactive carbonyls at ng to μg/mask levels. Naphthalene was the most abundant mask-borne PAH, accounting for over 80% of total PAH levels; acrolein, a mutagenic carbonyl, was detected in most of the mask samples, and di(2ethylhexyl) phthalate, an androgen antagonist, was detected in one-third of the samples. Furthermore, there is large mask-to-mask variability of the residue VOCs, revealing the uneven quality of masks. We confirm that masks containing more residue VOCs lead to significantly higher exposure levels and associated disease risks to the wearer, which should warrant the attention of the general public and regulatory agencies. We find that heating the masks at 50 °C for as short as 60 min lowers the total VOC content by up to 80%, providing a simple method to limit our exposure to maskborne VOCs.

In this study, we assessed the feasibility of using ordinary face masks as a sampling means to collect airborne polycyclic aromatic hydrocarbons (PAHs). Nonwoven fabric masks can trap three-ring or larger PAHs at a high efficiency (>70%) and naphthalene at ∼17%. The sampling method is quantitative as confirmed by comparison with the standard method of the National Institute for Occupational Safety and Health. In conjunction with sensitive fluorescence detection, the method was applied to quantify nine airborne PAHs in a range of indoor and outdoor environments. Wearing the mask for 2 h allowed quantification of individual PAHs as low as 0.07 ng/m3. The demonstration shows applicability of the method in monitoring PAHs down to ∼30–80 ng/m3 in university office and laboratory settings and up to ∼900 ng/m3 in an incense-burning temple. Compared with traditional filter-/sorbent tube-based approaches, which require a sampling pump, our new method is simple, convenient, and inexpensive. More importantly, it closely tracks human exposure down to the individual level, thus having great potential to facilitate routine occupational exposure monitoring and large-scale surveillance of PAH concentrations in indoor and outdoor environments.

Balkan endemic nephropathy (BEN) is a chronic tubulointerstitial nephropathy affecting residents of rural farming areas in many Balkan countries. Although it is generally believed that BEN is an environmental disease caused by multiple geochemical factors with much attention on aristolochic acids (AAs), its etiology remains controversial. In this study, we tested the hypothesis that environmental contamination and subsequent food contamination by polycyclic aromatic hydrocarbons (PAHs) and phthalate esters are AA toxicity factors and important to BEN development. We identified significantly higher concentrations of phenanthrene, anthracene, diethyl phthalate (DEP), dibutyl phthalate (DBP), and benzyl butyl phthalate (BBP) in both maize and wheat grain samples collected from endemic villages than from nonendemic villages. Other PAHs and phthalate esters were also detected at higher concentrations in the soil samples from endemic villages. Subsequent genotoxicity testing of cultured human kidney cells showed an alarming phenomenon that phenanthrene, DEP, BBP, and DBP can interact synergistically with AAs to form elevated levels of AA-DNA adducts, which are associated with both the nephrotoxicity and carcinogenicity of AAs, further increasing their disease risks. This study provides direct evidence that prolonged coexposure to these environmental contaminants via dietary intake may lead to greater toxicity and accelerated development of BEN.