Hi Cindy, if I was in San Fran. or any other hi populated area I might agree. I live in the country outside a small town (main street downtown is two blocks long) Michigan. Every time I drive in or out of my dirt drive I put more dust in the air than my outside vent does. All my neighbors use chain saws to trim down branches after storms and the saw dust generated is far more than I collect in the trash can seperater in 3 months of use. True, I will have some pr and exotic wood in there, but some pen blank turnings are miniscule in the big picture here. My system is a HF 2 hp collector. The 30 gallon galvanized trash can is in line just before the DC with the woodcraft cyclone lid (part # 143290). The bag and stand from the dc are removed completely and stored. That bag is a good dust filter for exhaust INSIDE a shop. but really restricts the air flow capacity of the blower. The hose that used to go into the bag is run out side thru the dryer vent. I have no dead bugs, plants or critters in the area, no neighbors have had any unusual allergies or reactions pop up, and in two years of use have yet to see any sign of dust on the ground or in the area. As far as getting sucked back into the shop, the vent is on the back wall, no windows or doors, no problem. 
PLEASE fellow members, I am responding to questions here, giving MY opinions about what works for me in my location with my equiptment.