Inadequate bedroom ventilation and poor air quality can negatively affect sleep. A recent international study found that the currently prescribed minimum ventilation rates for residential buildings, and especially bedrooms, may be too low and result in disturbed sleep. Therefore, they recommended revisiting the relevant residential building standards so that the ventilation rate with outdoor air can keep CO₂ produced by sleeping occupants at least below 1,000 ppm, or preferably below 800 ppm.

Hair graying and melanoma—a form of skin cancer—may seem like unrelated phenomena. But according to a new study from The University of Tokyo, both outcomes may arise from how pigment-producing stem cells respond to DNA damage. These cells, located in hair follicles, face a critical decision under genotoxic stress: either to differentiate and exit the system—leading to graying—or to continue dividing, which may eventually lead to tumor formation.