Venting

Until recently, we had a open pipe in our basement that was conected to our main wastepipe. The copper tube from our hot water heating system saftety valve ran into it. Upon the advise of our plumber, we had this sealed off and are glad we did because the basement no longer has odors it once had.We are now concerned that the pipe may have been allowing sewer gases into our home that may have presented health hazards, is there any info on such potential health hazards?Thank you.