Why are our bogies green?

Question

I mean, all day we breathe in dust and exhaust fumes and assuming they are grey/brown, why does one produce green bogies?

The most logical answer will get 10 points.

Answer 1

Neither healthy bogies or phlegm is really green. It becomes so in the presence of infection because of the large numbers of white blood cells present, which make their way through the airway walls to combat the infection. They also give pus a whitish-green colour.

Answer 2

Pooh, try a day in London, they will be black for a while, no kidding.

But I think nature made them green so they look tasty to kids.

Answer 3

mucus is naturally clear. if it is green or yellow when it is wet then you have an infection. when it's dry it tends to be colour of dust and is therefore usually grey/green or red/brown if you have had nosebleed. it can also be blue if you get certain infections. i try not to study mine too much

Answer 4

why pick on them ? are you colour prejudiced. ?  

Answer 5

How disgusting... what a question... uuuhhhh...

Answer 6

I think it must be something to do with the bacteria in amongst all the gunk. I'm no expert though!

Answer 7

Your nose is the most aerated and moist and supplies unlimited quantities of bacterial food secreted continuously by the nasal mucosa. It contains glycoprotein and dissolved salts. In other words, it is a breeding ground for bacteria which are always present.

Many of the common bacteria associated with humans are coloured , staphyclococcus aureus is a golden yellow for example, and pseudomonas pyocyanea (to be precise) is a shade of blue! Normally there and a multitude of other organisms that are inhaled continuously into the nose are flushed out by the runny mucus, which is swallowed. The bacteria are usually digested.

However, if a situation arises where the flow of mucus slows down and then becomes much thicker in response to an infection of any kind, then the bacteria , in their ideal home, can multiply and produce the colour mucus as you described. This as many parents know is one of the less endearing characteristics of babies and young children!

And if you are wondering where the green comes from, remember what happens when you mix blue and yellow.