Organic ultraviolet filters are widely used in personal care products. 4-methylbenzylidene camphor (4-MBC) is one of the most frequently used UV filters. Due to its widespread usage 4-MBC has been detected at high concentrations in offshore waters. Previous toxicological studies have suggested that 4-MBC might induce much higher toxicity in marine organisms than freshwater species. To explore the effects of salinity on 4-MBC toxicity, the marine copepod Tigriopus japonicus was used as the model species, as it plays an important role in marine ecosystems and can be adapted to a wide range of salinity conditions. T. japonicus were adapted to three different salinity conditions (i.e., 20, 30 and 40 ppt) prior to exposure to 0, 1, and 5 μg L⁻¹ 4-MBC for multiple generations (F0-F3). Results showed that environmentally relevant concentrations of 4-MBC had toxic effects on T. japonicus and therefore, can pose a significant risk to marine copepods in the natural environment. In addition, increasing salinity levels increased the lethal, developmental and reproductive toxicities of 4-MBC in T. japonicus. This was because that higher salinity levels increased the uptake rate constant and bioconcentration factor of 4-MBC and also further exacerbated the oxidative stress induced by exposure to 4-MBC in T. japonicus. Our study demonstrated that understanding how salinity affects the toxicity of 4-MBC is important for accurate assessment of the risk of 4-MBC in the aquatic environments.

有机紫外线过滤器广泛用于个人护理产品。4-甲基亚苄基樟脑（4-MBC）是最常用的UV过滤剂之一。由于其广泛使用，已在离岸水中以高浓度检测到4-MBC。先前的毒理学研究表明4-MBC在海洋生物中的毒性可能比淡水物种高得多。为了研究盐度对4-MBC毒性的影响，以海洋co足类Tigriopus japonicus为模型物种，因为它在海洋生态系统中起着重要作用，并且可以适应多种盐度条件。在暴露于0、1和5μgL ^-1之前，将日本血吸虫适应了三种不同的盐度条件（即20、30和40 ppt）多代使用4-MBC（F0-F3）。结果表明，与环境有关的4-MBC浓度对日本血吸虫有毒作用，因此，在自然环境中可能对海洋pe足类动物构成重大风险。此外，盐度水平的提高还增加了日本血吸虫中4-MBC的致死，发育和生殖毒性。这是因为较高的盐度水平提高了4-MBC的吸收速率常数和生物富集因子，并且进一步加剧了日本血吸虫暴露于4-MBC引起的氧化应激。我们的研究表明，了解盐度如何影响4-MBC的毒性对于准确评估水生环境中4-MBC的风险很重要。