When oil is spilled into the environment its toxicity is affected by abiotic conditions. The cumulative and interactive stressors of chemical contaminants and environmental factors are especially relevant in estuaries where tidal fluctuations cause wide variability in salinity, temperature, and ultraviolet (UV) light penetration, which is an important modifying factor for polycyclic aromatic hydrocarbon (PAH) toxicity. Characterizing the interactions of multiple stressors on oil toxicity will improve prediction of environmental impacts under various spill scenarios. This study examined changes in crude oil toxicity with temperature, salinity, and UV light. Oil exposures included high-energy, water-accommodated fractions (HEWAFs) and thin oil sheens. Larval (24–48 h post hatch) estuarine species representing different trophic levels and habitats were evaluated. Mean 96 h LC₅₀ values for oil prepared as a HEWAF and tested under standard conditions (20 ppt, 25 °C, No-UV) were 62.5 µg/L tPAH₅₀ (mud snails), 198.5 µg/L (grass shrimp), and 774.5 µg/L (sheepshead minnows). Thin oil sheen 96 h LC₅₀ values were 5.3 µg/L tPAH₅₀ (mud snails), 14.7 µg/L (grass shrimp), and 22.0 µg/L (sheepshead minnows) under standard conditions. UV light significantly increased the toxicity of oil in all species tested. Oil toxicity also was greater under elevated temperature and lower salinity. Multi-stressor (oil combined with either increased temperature, decreased salinity, or both) LC₅₀ values were reduced to 3 µg/L tPAH₅₀ for HEWAFs and < 1.0 µg/L tPAH₅₀ for thin oil sheens. Environmental conditions at the time of an oil spill will significantly influence oil toxicity and organismal response and should be taken into consideration in toxicity testing and oil spill damage assessments.

当石油泄漏到环境中时，其毒性会受到非生物条件的影响。在潮汐波动导致盐度，温度和紫外线（UV）穿透率变化很大的河口中，化学污染物和环境因素的累积和相互作用压力因子尤其重要，这是多环芳烃（PAH）毒性的重要调节因素。表征多种压力源对石油毒性的相互作用将改善在各种溢油情景下对环境影响的预测。这项研究检查了原油毒性随温度，盐度和紫外线的变化。石油暴露包括高能量，水可吸收馏分（HEWAF）和稀油光泽。评估了代表不同营养水平和栖息地的幼体（孵化后24-48小时）河口物种。平均96小时LC制成HEWAF并在标准条件下（20 ppt，25°C，无紫外线）进行测试的油的₅₀值为62.5 µg / L tPAH ₅₀（泥蜗牛），198.5 µg / L（草虾）和774.5 µg / L（小head鱼）。在标准条件下，稀油光泽96 h的LC ₅₀值为5.3 µg / L tPAH ₅₀（泥螺），14.7 µg / L（草虾）和22.0 µg / L（草皮min鱼）。紫外线在所有测试物种中均显着增加了油的毒性。在高温和低盐度下，油的毒性也更大。对于HEWAF，多应力源（油与温度升高，盐度降低或两者兼而有之相结合）的LC ₅₀值降低至3 µg / L tPAH ₅₀，而<1.0 µg / L tPAH ₅₀适用于稀薄的油光。漏油时的环境条件将严重影响油的毒性和机体反应，因此在毒性测试和漏油损害评估中应予以考虑。