"The capital expenditures for ponds are attractive, but the low growth numbers and high contamination rates in these simple open systems have stalled investors from seeing enough value to invest."

Important information that was not reported includes the contamination rate in the control group, and the treatment administered to the prostate cancer cases by stage and by randomly assigned group.

Previous studies have found similar contamination rates in other cities.

The length of the shoots in various plants was four to six times greater, and the contamination rate was also sharply lower.

The average contamination rate for 2001 is 1.64 picocuries per gram, Mr. Green said.

The consequences, some public health advocates argue, show clearly in the department's own statistics: contamination rates for salmonella and E. coli both increased from 2000 to 2001.

In some months, he said, the contamination rate approached 100 percent.

The chicken industry denies any connection between the lack of enforcement and the increase in contamination rates, but it agrees that salmonella levels have been going in the wrong direction.

Since the U.S. contamination rate was based on a study of companies that routinely checked for mycoplasma, the actual contamination rate may be higher.

European contamination rates are higher and that of other countries are higher still (up to 80% of Japanese cell cultures).