Benzophenone-3 sunscreen causes phytotoxicity and cytogenotoxicity in higher plants.

The benzophenone-3 (BP-3) sunscreen is recurrently released into the environment from different sources, however, evaluations of its adverse effects on plants do not exist in the literature. In this study, BP-3 was evaluated, at concentrations 2; 20, and 200 µg/L, regarding phytotoxicity, based on germination and root elongation in seeds, in Lactuca sativa L., Cucumis sativus L. and Allium cepa L., and phytotoxicity, cytogenotoxicity and oxidative stress in A. cepa bulb roots. The BP-3 concentrations, except for the 200 µg/L concentration in L. sativa, caused no significant reduction in seed germination. All concentrations tested significantly reduced the elongation of roots from seeds and roots from bulbs. The 20 and 200 µg/L concentrations caused oxidation in cells, disturbances in the cell cycle, and alterations in prophase and metaphase, as well as the induction of micronuclei, in A. cepa root meristems. Furthermore, the three concentrations induced a high number of prophases in root tips. Such disorders were caused by excess H2O2 and superoxide produced in cells due to exposure to BP-3, which triggered significant phytotoxicity, cytotoxicity, and genotoxicity in root meristems. Thus, the recurrent contamination of agricultural and non-agricultural soils with BP-3, even at a concentration of 2 µg/L, represents an environmental risk for plants. These results point to the impending need to set limits for the disposal of this sunscreen into the environment since BP-3 has been used in industry for several decades.

Toxicity of methylparaben and its chlorinated derivatives to Allium cepa L. and Eisenia fetida Sav.

Methylparaben, chloro-methylparaben, and dichloro-methylparaben were evaluated in Allium cepa at 5, 10, 50, and 100 µg/L and in Eisenia fetida at 10 and 100 µg/L. In A. cepa roots, 100 µg/L methylparaben and 50 and 100 µg/L chlorinated methylparabens reduced cell proliferation, caused cellular changes, and reduced cell viability in meristems, which caused a reduction in root growth. Furthermore, they caused drastic inhibition of catalase, ascorbate peroxidase, and superoxide dismutase; activated guaiacol peroxidase and promoted lipid peroxidation in meristematic root cells. In earthworms, after 14 days exposure to the three compounds, there were no deaths, and catalase, ascorbate peroxidase, and superoxide dismutase were not inhibited. However, guaiacol peroxidase activity and lipid peroxidation were observed in animals exposed to dichloro-methylparaben. Soils with dichloro-methylparaben also caused the escape of earthworms. It is inferred that the recurrent contamination of soils with these methylparabens, with emphasis on chlorinated derivatives, can negatively impact different species that depend directly or indirectly on soil to survive.

Prospecting toxicity of octocrylene in Allium cepa L. and Eisenia fetida Sav.

Octocrylene sunscreen is found in different environmental compartments. Unlike aquatic organisms, there are few studies evaluating the adverse effects caused by this pollutant on terrestrial plants, and no studies on soil fauna. In this study, octocrylene was evaluated at concentrations of 10, 100, and 1000 µg/L for phytotoxicity, cytogenotoxicity, and oxidative stress in Allium cepa L., and acute toxicity and oxidative stress in Eisenia fetida Sav. In A. cepa, at concentrations of 100 and 1000 µg/L, octocrylene reduced the germination potential in seeds, inhibited root elongation, and caused disturbance in cell division in roots. In E. fetida, the concentration of 1000 µg/L promoted an avoidance rate of 80%, while 10 µg/L caused a hormesis effect. The concentrations 100 and 1000 µg/L caused lipid peroxidation in A. cepa and E. fetida. Based on the results, the recurrent use of biosolids in soil fertilization, as well as the irrigation of plants with wastewater, with the presence of octocrylene can negatively impact the survival of different species that depend directly or indirectly on the soil.