Biotoxicity of water-soluble species in PM2.5 using Chlorella. (July 2019)

• Record Type: Journal Article
• Authors: Yang, Liu; Duan, Fengkui; Tian, Hua; He, Kebin; Ma, Yongliang; Ma, Tao; Li, Hui; Yang, Shuo; Zhu, Lidan
• Is Part Of: Environmental pollution. Volume 250(2019)
• Page Start: 914
• Page End: 921
• Publication Date: 2019-07
• Subjects: Toxicity -- Water-soluble species in PM2.5 -- Chlorella -- Chlorophyll a -- Chlorophyll fluorescence -- Cell microstructure; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2019.04.017
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: China has been faced with severe haze pollution, which is hazardous to human health. Among the air pollutants, PM2.5 (particles with an aerodynamic diameter ≤ 2.5 μm) is the most dangerous because of its toxicity and impact on human health and ecosystems. However, there has been limited research on PM2.5 particle toxicity. In the present study, we collected daily PM2.5 samples from January 1 to March 31, 2018 and selected samples to extract water-soluble species, including SO4 2−, NO3 −, WSOC, and NH4 + . These samples represented clean, good, slight, moderate, and heavy pollution days. After extraction using an ultrasonic method, PM2.5 solutions were obtained. We used Chlorella as the test algae and studied the content of chlorophyll a, as well as the variation in fluorescence when they were placed into the PM2.5 extraction solution, and their submicroscopic structure was analyzed using transmission electron microscopy (TEM). The results showed that when the air quality was relatively clean and good (PM2.5 concentration ≤ 75 μg m −3 ), the PM2.5 extraction solutions had no inhibiting effects on Chlorella, whereas when the air quality was polluted (PM2.5 concentration > 75 μg m −3 ) and heavily polluted (PM2.5 concentration > 150 μg m −3 ), with increasing PM2.5 concentrations and exposure time, the chlorophyll a content in Chlorella decreased. Moreover, the maximum photochemical quantum yield (Fv /Fm ) of Chlorella obviously decreased, indicating chlorophyll inhibition during polluted days with increasing PM2.5 concentrations. The effects on the chlorophyll fluorescence parameters were also obvious, leading to an increase of energy dissipated per unit reaction center (DIo /RC), suggesting that Chlorella could survive when exposed to PM2.5 solutions, whereas the physiological activities were significantly inhibited. The TEM analysis showed that there were few effects on Chlorella cell microstructure during clean days, whereas plasmolysis occurred during light- and medium-polluted days. With increasing pollution levels, plasmolysis became more and more apparent, until the organelles inside the cells were thoroughly destroyed and most of the parts could not be recognized. Graphical abstract: Image 10184 Highlights: PM2.5 samples in different pollution level days were extracted for the main water-soluble species, including SO4 2−, NO3 −, WSOC, and NH4 + . With the increase of PM2.5 level, the inhibiting effects on chlorophyll A, chlorophyll fluorescence in Chlorella, became more obvious. With the increase of PM2.5 level, the plasmolysis of the Chlorella cell became more apparent, until the organelles were thoroughly destroyed. Abstract : PM2.5 showed obvious toxicity on Chlorella chlorophyll a, fluorescence, and the cell microstructure with increasing concentrations and exposure time.