You completely missed the point. 400% is meaningless without more context. If I increase my odds of winning the lottery by 400%, I’d still be a moron for wasting my money in the lottery. Percentages are constantly abused in marketing and news articles to imply things that don’t really apply.

So yes, the article doesn’t actually specify how much your risk increases due to being exposed to those chemicals, just saying 400% is about as informative as saying 6 or 10,000. It implies a significant risk, but doesn’t support it. Without knowing how much risk there actually is it’s impossible to evaluate if the benefits outweigh the risks.