Symptoms from refinery

I was doing outreach work on Glade and Doyle near the tricor refinery. Every single person that I talked to told me that there is almost always a strong smell of either crude, oil, or rotten eggs. Every single person also mentioned that the smells usually get bad at around 11:00 a.m. to 2:00 a.m.. I had to leave the area because I was experiencing a headache and a dry and irritated throat. The symptoms went away a few minutes after I left the area.
I was using a Aries Pico methane monitor that showed a high correlation that there was gas presence in the air. The methane stayed above 3 PPM the entire time and climbed up to around 4 in certain areas