RESUMEN
Based on the online monitoring data of volatile organic compounds(VOCs) and ozone(O3) in Liaocheng in June 2021, the concentration levels, compositional characteristics, daily variation characteristics, and ozone formation potential(OFP) of VOCs on polluted days and clean days were systematically analyzed. Potential source areas of VOCs were identified by the potential source contribution function(PSCF) and concentration-weighted trajectory(CWT). The sources of VOCs in Liaocheng were analyzed using the characteristic species ratio and positive matrix factorization(PMF). The results showed that the hourly mean values of VOCs concentrations on polluted days and clean days in Liaocheng in June 2021 were(115.38±59.12) µg·m-3 and(88.10±33.04) µg·m-3, respectively, and the concentration levels of VOCs in each category showed that oxygenated volatile organic compounds(OVOCs)>alkanes>halogenated hydrocarbons>aromatic hydrocarbons>alkenes>alkynes>organosulfur. VOCs species with large differences in concentrations between polluted and clean days were among the top ten species of the hourly mean VOCs concentrations. The daily trends of concentrations of total VOCs, alkanes, alkynes, aromatic hydrocarbons, halogenated hydrocarbons, and organosulfur showed that the daytime concentrations were lower than the nighttime concentrations, and the daily changes in OVOCs concentrations showed the characteristics of high in the daytime and low at nighttime. The OFP was 285.29 µg·m-3 on polluted days and 212.00 µg·m-3 on clean days, and OVOCs, alkenes, and aromatic hydrocarbons contributed significantly to ozone formation. The PSCF and CWT results found that the potential source areas of VOCs in Liaocheng were concentrated in the northern and northeastern part of Dongchangfu District and the central and southwestern part of Chiping District. The results of the characteristic species ratio indicated that the VOCs in Liaocheng might have been more from coal combustion, gasoline volatilization, and motor vehicle exhaust. The results of PMF showed that industrial emission sources(30.57%), motor vehicle exhaust and oil and gas volatilization sources(19.44%), combustion sources(17.23%), air aging and secondary generation sources(13.69%), solvent usage sources(12.75%), and natural sources(6.32%) were the main sources of VOCs in Liaocheng.
RESUMEN
BACKGROUND: Both programmed cell death-1 (PD-1) inhibitors and lenvatinib, which have a synergistic effect, are promising drugs for tumor treatment. It is generally believed that combination therapy with a PD-1 inhibitor and lenvatinib is safe and effective. However, we report a case of toxic epidermal necrolysis (TEN), a grade 4 toxicity, after this combination therapy. CASE SUMMARY: A 39-year-old male presented with erythema, blisters and erosions on the face, neck, trunk and limbs 1 wk after receiving combination therapy with lenvatinib and toripalimab, a PD-1 inhibitor. The skin injury covered more than 70% of the body surface area. He was previously diagnosed with liver cancer with cervical vertebra metastasis. Histologically, prominent necrotic keratinocytes, hyperkeratosis, liquefaction of basal cells and acantholytic bullae were observed in the epidermis. Blood vessels in the dermis were infiltrated by lymphocytes and eosinophils. Direct immunofluorescence staining was negative. Thus, the diagnosis was confirmed to be TEN (associated with combination therapy with toripalimab and lenvatinib). Full-dose and long-term corticosteroids, high-dose intravenous immunoglobulin and targeted antibiotic drugs were administered. The rashes gradually faded; however, as expected, the tumor progressed. Therefore, sorafenib and regorafenib were given in succession, and the patient was still alive at the 10-mo follow-up. CONCLUSION: Cautious attention should be given to rashes that develop after combination therapy with PD-1 inhibitors and lenvatinib. Large-dose and long-course glucocorticoids may be crucial for the treatment of TEN associated with this combination treatment.
