Abstract：
PFAS, or per- and polyfluoroalkyl substances, are a family of man-made chemicals found in a variety of products from non-stick cookware and food wrappers to firefighting foams. PFAS are persistent and widely distributed in the environment, including aquatic environments. In this study we examined the impact of PFAS chemicals on the physiological and behavioral endpoints of Lumbriculus variegatus (i.e., blackworms). Lumbriculus variegatus is a species of freshwater annelid worm that plays key roles in shallow freshwater ecosystems. At an environmentally relevant concentration of 1 μg/L, 12-day aqueous exposure to long chain PFAS, including PFOA, PFOS and PFDA, each markedly slowed the pulse rate of the dorsal blood vessel in L. variegatus, indicating a suppressive effect on blood circulation. The mean pulse rate was reduced from 9.6 beats/minute to 6.2 and 7.0 beats/min in PFOA and PFOS, respectively (P < 0.0001). Further, PFOA, PFOS and PFDA reduced the escape responsiveness of L. variegatus to physical stimulation. The percentage of worms showing normal escape behavior was reduced from 99.0% in control to 90.6% in the PFOS exposed group (P < 0.01). In a chronic (4 week) growth study, exposure to overlying water and sediment spiked with PFOA, PFOS or PFDA reduced the total biomass and the number of worms, indicating a suppressive effect on worm population growth. For instance, PFOA and PFDA reduced the total dry biomass by 26.3% and 28.5%, respectively, compared to the control (P < 0.05). The impact of PFAS on blackworm physiology is accompanied by an increase in lipid peroxidation. The level of malondialdehyde (MDA), an indicator of lipid peroxidation, and catalase, a major antioxidant enzyme, were markedly increased in PFOA, PFOS and PFDA exposed groups. Interestingly, exposure to PFHxA, a short chain PFAS, had no detectable effect on any of the measured endpoints. Our results demonstrate that L. variegatus is highly sensitive to the toxic impact of long chain PFAS chemicals as measured by multiple endpoints including blood circulation, behavior, and population growth. Such toxicity may have a detrimental impact on L. variegatus and the freshwater ecosystems where it resides.
摘要：
PFAS,或全氟烷基和多氟烷基物质，从不粘锅炊具和食品包装到消防泡沫等多种产品中都有一系列人造化学物质。PFAS具有持久性，在环境中分布广泛，包括水生环境。在这项研究中，我们研究了PFAS化学物质对Lumbriculusvariegatus生理和行为终点的影响（即，黑虫）。Lumbriculusvariegatus是一种淡水环形虫，在浅层淡水生态系统中起着关键作用。在环境相关浓度为1μg/L时，12天水性接触长链PFAS，包括PFOA,全氟辛烷磺酸和PFDA，每个都显着减慢了变异乳杆菌背侧血管的脉搏率，对血液循环有抑制作用.PFOA和PFOS的平均脉搏率从9.6次/分钟降低到6.2和7.0次/分钟，分别为(P<0.0001)。Further,PFOA,PFOS和PFDA降低了变异乳杆菌对物理刺激的逃逸反应。显示正常逃逸行为的蠕虫百分比从对照组的99.0％降低到全氟辛烷磺酸暴露组的90.6％（P<0.01）。在一项慢性（4周）生长研究中，暴露于掺有PFOA的上覆水和沉积物中，全氟辛烷磺酸或PFDA减少了总生物量和蠕虫的数量，表明对蠕虫种群增长有抑制作用。例如,PFOA和PFDA减少了总的干生物量26.3％和28.5％，分别,与对照组相比(P<0.05)。PFAS对黑虫生理的影响伴随着脂质过氧化的增加。丙二醛（MDA）的水平，脂质过氧化的指标，和过氧化氢酶,一种主要的抗氧化酶，PFOA明显增加，全氟辛烷磺酸和PFDA暴露组。有趣的是,暴露于PFHxA，短链PFAS,对任何测量的端点没有可检测的影响。我们的结果表明，变异乳杆菌对长链PFAS化学物质的毒性影响高度敏感，通过包括血液循环在内的多个终点来衡量，行为，和人口增长。这种毒性可能对变形虫及其所在的淡水生态系统产生不利影响。
