I just read about the concept of menstrual leave. The Wikipedia article says it originated in Japan, and applies in a couple of asian countries.
In 2005, Australian Manufacturing Workers Union secretary Doug Cameron asked for menstrual leave to be available for women working at Toyota (in Australia):
"Many women have excessive cramps, many women have headaches, many women have nausea, many women can't concentrate and they're on a production line," he said.
"It's a tough, hot dangerous job and we believe that this is a sensible claim that's good for the company because it will improve productivity, it will improve quality and it will improve health and safety."
Does menstruation affect the ability of a significant number of women to do blue-collar work?