Usually we all thought of hygiene and health starts from within rather from outside environment. But actually health emerges from pure and sure atmosphere ie. from periphery to centre (Centrifugal in nature). The ultimate epitome of providing potentially sure and pure atmosphere is the green plantations like sincerely planting the trees with utmost care and dedication in which you can emphasize the Divine and humanity.
Here is why I am strongly emphasizing the green plantations; say for real (virtual) example, a single broad leaf of a plantain tree generates more than 40 litres of oxygen per day the eternal life giving pollutant less air upon which all the living-beings solely depends for survival prior to water and food. Think of natural world how they tirelessly without single penny expectation nourishes the living-beings.