NASA and JPL project managers look at the environmental assessment process as a bother and an annoyance. It shows in their documents and in their discussions. Engineers are trained to downplay risks. They consider a one in a million risk insignificant. But to a lay person who has seen the results of thousands of environmental accidents where the risk was supposedly very low, one in a million seems quite possible.
Engineers assume that their audience is making the same numerical assumptions that they do.
Modern science condones illness, cancers, and even possible deaths if they advance a technology or turn a profit. The Food and Drug Administration says it is OK that 6,000 people per year die from infected meat products. The Federal Aviation Administration will not order an airline safety measure unless the cost to implement it is less than the cost of paying the wrongful death lawsuits of the estimated victims. Most of our national environmental standards are based on the assumption that it is OK for a certain number of people to become ill, even fatally so. To a scientist or engineer trained by Western standards, it is acceptable to risk people's lives for the sake of the scientific objectives.