It's a vitamin - that means it's required for survival.
Too much MIGHT make you sick - too little will kill you.
No, Cobalamin (B12) is a vitamin necessary to the human body.
microsporium is a terrible fungi that is harmful to human beings
No.
Radioactive particles include alpha beta and positron they are not so harmful for human body the actually harmful are gamma radiations associated with these particles.
some harmful radiations reach to earth and can damage skin of human beings and plants
mice can sometimes spread diseases that can kill numorus numbers of human beings and such.
Ozone layer is very important for human beings. It protects us from the harmful UV radiations of the sun.
polluted water is harmful for animals and human beings who drink water from well.it is also harmfull for plants which are getting water from pollted groundwater.
Ozone depletion protects us from UV rays. These rays are harmful for human beings.
Generally indigestion tablets are not harmful but useful. But excess of use or some other health problems of some individuals can lead to harmful effects. See the link below.
they are not harmful to the environment
The two main disadvantages of mosquitoes are that they are a pest and they are an irritant to human skin. When you get bit by a mosquito you will get a swollen, itchy spot.