The FDA has released preliminary data regarding the levels of the carcinogen NDMA found within various brands of valsartan, the reasonable safe levels of NDMA, and the increased risk of cancer associated with contaminated valsartan. However, the FDA does not indicate what materials or math it used to come to reasonable safe level or increased risk of cancer due to contaminated valsartan. The FDA stated that the reasonable safe level for NDMA consumption per day is 0.098 micrograms (mcg or µg). As the investigation has progressed, the FDA has now detected NDMA levels within valsartan ranging from 0.3 mcg to 20 mcg! That means some lots of contaminated valsartan have over 200 times the reasonably safe daily dose of NDMA. Currently, the FDA has only released results from 23 out of several hundred lots of contaminated valsartan. The FDAs initial assessment (before all the high NDMA results were confirmed) was that if 8,000 people ingested the highest valsartan dose (320 mg) contaminated with NDMA for four years, there may be one additional case of cancer over the lifetime of the 8,000 people.
Below is a graph from a 2015 meta-analysis on daily intake of NDMA in food and the increased risk of gastric cancer. At just 0.3 µg per day, which is the same amount of NDMA found in Hetero Labs contaminated valsartan (µg = mcg), the risk of bowel cancer increases 70%. Higher doses of NDMA have not been tested in humans, because it would be unethical do to so. Therefore, it’s hard to know the increased risk and additional side effects that 20 mcg per day of NDMA would cause. The authors from the 2015 NDMA meta-analysis also noted that gastric cancer risk increased “following an increase of NDMA intake up to 0.12 µg /day”