It depends on the scale.
Some organizations only use a scale up to 12,
If that number is supposed to be pieces per million it is very small.
But, the Asthma Foundation uses a scale where 39 is low. A moderate number would be near 80. (This scale makes the most sense with your number)
39% = 39/100
Approximately 39 ft at its tallest point and over 2150 miles long.
The lowest melting point is of course - 39 0C.
Yes, if you are allergic to it. There all sorts of pollen and the main ones that cause hayfever are grass tree and weed pollens. Mould spores also trigger allergies. It all depends on your sensitivity level or trigger point. If you have a low trigger point to a particular allergen - whether it is pollen or dust or pet dander - then it won't take much of that allergen getting in to your body through your nose to trigger your reaction. If you have a high trigger point then you might only get a reaction on the worst of the pollen days - or maybe you won't react at all because you never reach your trigger level. So reducing the amount of allergen in your immediate vicinity will help with hayfever. That's why people use pollen blockers and pollen barriers on their nose, and it's also why air purifiers in the home can be helpful.
I believe it's the wind. High levels of wind can blow the pollen right off the flower.
mercury
I believe it to be -39 degrees Celsius, but I am not sure.
-pollen sticks to the stigma at the end of the pistil -pollen tubes grow down the pistil to the egg cells -sperm cells from the pollen moves down the tubes -fertilization combines DNA
Mercury
West Point - 1956 Pressure 1-39 was released on: USA: 28 June 1957
low:-39 High:137
39 inches is the height of Varsity 110m hurdles for men. JV is 36 inches.