In recent times there has been an increasing publication of studies indicating that not only do the standard surgical style face masks fail to stop disease transition, and infection, being largely good for particle protection, but that masks have adverse effects, in themselves. A Germany study has indicated that wearing masks for long periods of time increases carbon dioxide exposure in the body. This in turn has a wide range of ill-health effects, and it does not take long, for wearing masks for more than 5 minutes can lead to chronic exposure of carbon dioxide of 1.41% to 3.2% of inhaled air, while the carbon dioxide content of air is only 0.04% carbon dioxide. The adverse effects include foetal defects and still births, neurotoxicity, and damage to the male reproductive system.
https://nakedemperor.substack.com/p/wearing-masks-can-increase-the-risk