Lighting, Light Fixtures, Ceiling and Exhaust Fans - Oxidation/Rust build-up on light sockets in ceiling light

I want to know why there is such a high build-up of oxidation/rust on the metal parts of my relatively new ceiling light fixtures?

We built a new home 3 years ago and all bedroom/family room/hallway lights are the same style having a dome with multiple bulb sockets that have metal parts rusting so much that the build-up rust dust is dropping in to the dome. The base is secured by two screws to the ceiling, they are rusting. The bracket the screws are secured to is rusting. There have been short bulb lives in these lights because of heat, I believe, as the part of the bulb facing the silver reflective foil, that covers a thin insulation layer on the base, is discolored. Even when I unscrew the light bulbs to change them, rust is shaken out with the vibration and sometimes the metal base of the light bulb itself is rusty. We have only used the recommended 60 watt bulbs and have never exceeded that wattage.

I inspected the wiring above and around a few of the most culprit fixtures and everything appears just fine. I was wondering if the electric sub-contractor did subpar work, but I now think it is the fixtures themselves that are poorly designed allowing a lot of heat to build up and cause the corrosion. We purchased all the fixtures in the house from a reputable dealer through our contractor, from the regular stock, not the knock-off section or anything.

My question is 1) if excessive heat could that cause such a high build up of rust in fixtures only a few years old? 2) If that is so, can anything be done to prevent it? 3) Is this a fire hazard waiting to happen that necessitates replacing all these fixtures?

Thanks for any advice/knowledge to impart!
DrewS

Rust is not caused by heat. Rust is caused by moisture and steel. Find and eliminate the moisture and you solve your problem.