University of Gdansk, Faculty of Oceanography and Geography, Institute of Oceanography, Department of Marine Chemistry and Environmental Protection, Al. Marszałka Piłsudskiego 46, 81-378 Gdynia, Poland.
University of Gdansk, Faculty of Oceanography and Geography, Institute of Oceanography, Department of Marine Chemistry and Environmental Protection, Al. Marszałka Piłsudskiego 46, 81-378 Gdynia, Poland.
Sci Total Environ. 2019 Aug 1;676:268-277. doi: 10.1016/j.scitotenv.2019.04.204. Epub 2019 Apr 15.
Using the blood of grey seal pups, the blood and milk of female grey seals inhabiting the Hel Marine Station of Gdansk University's Institute of Oceanography (HMS), we monitored the transfer of total mercury (THg), methylmercury (MeHg), and selenium (Se) with blood during foetal life and nursing. Changes in the concentration of mercury and selenium were characterised in the pups' blood during their first three months of life when they transition from suckling, to a post-weaning fast, to eating fish. In the blood of pregnant females, there was a significant decrease in THg and MeHg concentrations throughout the gestation, indicating the transfer of these toxins through the placenta into the foetus. At no other stage of the pup's development was there such a high level of THg and MeHg as on the day of birth, despite the incorporation of mercury into the lanugo during foetal growth. This suggests that the maternal transfer of mercury during gestation may be the time of greatest mercury exposure for a young seal pup. The consumption of milk caused a rapid increase in weight and a lowering of the mercury level in the blood in the subsequent days of the pups' life. The postweaning fast was the period of the lowest mercury concentration. The switch to a diet consisting of fish caused a systematic increase in the concentration of mercury in the blood of the pups. Milk was the significant source of selenium for pups and the selenium concentration in females' blood was reduced during lactation. The nursing period seemed to have the greatest impact on the mercury and selenium blood levels in examined seals. Natural development of the grey seal pup created an opportunity to decrease the levels of toxic substances obtained through the maternal transfer during foetal growth.
利用灰海豹幼崽的血液、栖息在格但斯克大学海洋学研究所（HMS）赫尔海洋站的雌性灰海豹的血液和乳汁，我们监测了总汞（THg）、甲基汞（MeHg）和硒（Se）在胎儿期和哺乳期通过血液的转移。在幼崽生命的头三个月，它们从哺乳过渡到断奶后快速进食再到吃鱼，血液中的汞和硒浓度发生了变化。在怀孕的雌性血液中，THg 和 MeHg 浓度在整个妊娠期显著下降，表明这些毒素通过胎盘转移到胎儿体内。在幼崽发育的任何其他阶段，血液中的 THg 和 MeHg 水平都没有出生那天高，尽管在胎儿生长过程中已经将汞纳入胎毛中。这表明，在妊娠期间，母体对汞的转移可能是幼海豹暴露于汞的最大时期。随后几天，随着体重的增加和血液中汞含量的降低，乳汁的消耗导致体重迅速增加。断乳后快速下降是汞浓度最低的时期。当幼崽开始吃鱼时，会导致血液中汞浓度系统增加。乳汁是幼崽获取硒的重要来源，而在哺乳期，雌性血液中的硒浓度会降低。哺乳期似乎对所检查的海豹血液中的汞和硒水平有最大的影响。灰海豹幼崽的自然发育为减少通过胎儿生长期间母体转移获得的有毒物质水平创造了机会。
