I found this VERY interesting. Nice find OP.

I have been living in the same house for about 20 years in Southern California.

AS of the last couple years i HAVE BEEN SMELLING some sort of smell in and around my neighborhood recently.

A few years ago my family was home and we began smelling a faint smell. It almost smelled like a natural gas leak. We began to smell it in the early afternoon and after about an hour or 2, the smell became amplified and was almost over bearing.

All of us were able to smell the strange smell and we were talking as to what it could be. It became stronger and stronger and at one point we could smell it in every room of the house.

I placed a call to the non-emergency help line. When i reached the operator she took down my information and stated that MANY other residents were reporting the strange smell. She said that there was NO SUCH GAS LEAK. About 20 minutes later a fire truck arrived and searched the area with a gasleak sniffer. They found nothing but they too could smell this sulfur/egg smell.

Since this incident a few years ago, i have smelled the same smell about 3 to 4 different occasions all with different intensities. However this is never something that happened when i was a child growing up here. WHATEVER it is, it just started happening within the last few years.