The offering to the fire never gets destroyed, it gets transformed. This is also a proven principle of the physical science that basically no substance disappears as such; it only changes its form. As we put oblations into Yajna with regard and devotion, those matters become subtler and get spread into the atmosphere in molecular forms. This is also a wonderful tool for reducing atmospheric pollution. The aromatic smoke that rises from Yajna-fire helps destroy inimical germs. Scientists from many countries agree that Yajna is also a great tool for reducing global warming. These conclusions have been drawn after extensive researches. Moreover, the smoke out of cow ghee (processed butter) offered to fire, reduces the effects of nuclear radiation dramatically.
Though Yajna has been practiced since time immemorial, still when we look at the modern scenario this seems to be far more necessary and important than ever before, thanks to the environmental pollution for the sake of modernization. It is essential to sustain the balance in ozone layer for ecological balance which is disturbed by the pollution. However, it can be kept pure and balanced through practices like Yajna. Ozone is transformed oxygen. Ozone volumes are found in the smoke of Yajna. Yajna helps generate very large volume of ozone gas, which eventually supports the ozone layer. This ozone acts as the safety shield for our earth. The ozone layer filters the solar radiations. It stops the harmful rays of sun from reaching the earth and allows only the radiations which are good for human life. This ensures and helps sustain the life on earth and reduces the risk of diseases. On the contrary, with the depletion or thinning of ozone layer, the life on earth would adversely be affected by the harmful solar radiations. For recouping the ozone layer, to reduce pollution, it is essential to conduct Yajna on a large scale. Yajna is the only tool for preserving the ecological balance and for environmental purification.
In addition to the physical benefits, Yajna offers spiritual advantages as well. The oblations poured into Yajna get divided into two parts. One is the material part- Sthool and the other is the invisible part known as Sookshm (subtle). The material part (Sthool) reaches the inert deities like the Sun, the Fire, the Water, the Air, the Space, and the Earth which help us in many ways in our living. And the other one, i.e. the Sookshm part purifies our inner self. The ill intentions of our heart vanish and the pious thoughts develop. This subtler part of Yajna takes away our mental impurities like jealously, hatred, sins, lust, anger, etc. During Yajna we chant Mantras; a divine ambience builds up in the atmosphere. The sound waves create mystical and subtle vibrations in the surroundings and that has a profound effect on our mind, on the human brain. There is tremendous effect of Hawan Yajna on stress, depression and mental illness.