Arsenic is essential to the body in low doses yet if the body accumulates more then 10-20 grams it can lead to lung, colon, or bladder cancers and has also be associated with heart issues.
Oxygen. Without it our respiration process would not work. With the ionic radical form of oxygen running loose in the body a lot of damage is done due to oxygen's very high electronegativity.
Bacteria can be helpful by deleting bad viruses and harmful by killing you
--------bob
CO2, Oxygen, Nitrogen, Ozone. Water vapour
Yes they do.
fungi is the cause of food moulds, and some skin rashes such as warts. So it can be infectious to the things it comes in contact with and potentially harmful to that organism.
Ozone
things are harmful to earth
Bacteria can be helpful by deleting bad viruses and harmful by killing you
--------bob
Like most things, oil can be either helpful or harmful, depending upon what you do with it.
All high frequency radiation e.g. X rays , gamma rays etc. are harmful to living things .
They are harmful to living things because they are higher energy waves.
Volcano's can be harmul by destroying lots of things when it errupts:)
The vehicles are helpful because it help in transport the things the vehicles are harmful because it increase the pollution
Zygomycetes are harmful to humans and other living things. Zygomycetes are fungi and an example of this is mold which is harmful when it gets into the lungs.
Because of you .. =))Simple pimple! Easy peasy! I would like to explain it ..It is harmful bcoz ur ugly! xDD
A bee is both harmful and useful