Yes. We've seen quite a dramatic change. I was a welder's helper back in the day, maybe 30 years ago. The ventilation systems are quite admirable now. You used to have black around the nose, and basically that doesn't exist now.
To Dr. Cherry, in terms of the exposure to chemicals that we just talked about with Mr. Tadic, you referenced some data looking into the higher risk of miscarriage. Do you know if it's due to that chemical exposure at work? Certainly even tradespeople with good ventilation are exposed to a certain extent. Is it exposure to the elements or is it the strenuous nature of the trades?