Answer:
Yes and no.
Every living organism needs a small amount of nitrogen to survive. Nitrogen helps make up DNA. Every time we breathe in, we are taking nitrogen in the air into our bodies, but our bodies can't use the nitrogen in this form, so it doesn't harm us in this way and we just exhale it right back out.
We can only get nitrogen in small amounts through the foods we eat. Nitrogen in this shape and form is not harmful to us.
However, nitrogen is the main reason for the holes in the ozone layer. Fertilizers and the burning of fossil fuels, for example, changes nitrogen into a harmful pollutant.