They were exposed to alcohol and their ability to synchronize circadian rhythms was studied. The results of the study were published in the journal Alcoholism: Clinical & Experimental Research. Circadian systems are responsible for coordinating multiple physiological systems with environmental factors. Most of our body processes are regulated in the circadian fashion including our health says David Earnest, a professor in the department of neuroscience and experimental therapeutics at Texas A&M University Health Sciences Center. Researchers exposed male Sprague-Dawley rats to high alcohol levels.
Exposure to alcohol during the third trimester when components of the circadian system in the brain are developing, can lead to long-lasting effects. In conclusion Thomas suggested that dysfunction of circadian systems may contribute to some of the behavioral problems observed in children with FASD. This is similar to the experience that one undergoes when he travels across a varied number of time zones from east to west. Some people will get accustomed to it quickly, and some will not, and may even experience some physical problems or illness because of effects on their immune system.
This can be explained in case of the Exxon Valdez and Chernobyl. The captain of the Exxon Valdez was working in shifts and also under the influence of alcohol and was unable to maintain a normal, necessary performance. With Chernobyl, the shift-work schedules were inappropriate and, at the time that the accident happened, poor mental and physical performances contributed to the disaster. The author says that there is currently no known safe amount of alcohol that can be consumed during pregnancy, so it is best to abstain from alcohol drinking during pregnancy.