However, the above 4 Key Elements for Human Life are either polluted or deteriorated, while we spend 90% of our time indoors. Current indoor artificial lighting, due to insufficient wavelengths and poor color quality, may cause depression, sleep disorders, diabetes, cancer and more. Air pollution causes millions of premature deaths every year. Unclean water quality causes all kinds of diseases. Improper temperature can present problems, including nasal congestion, breathing problems, headache, fatigue and irritated skin.