All from Leeds - mainly Hunslet and Holbeck. I haven't yet gone into parish records as I am a single mother with a 9 year old autistic son and don't have time to drive to Leeds and back while he's at school.
I have bmd certificates and census evidence back to a Charles Atha born about 1819 in Leeds and have been told that his father was called George Atha (b.19 Oct 1778 in Holbeck, Leeds). I think the person that gave me this information had looked into parish records, but I couldn't swear to it. According to this person George's father was called Samuel (b.1748 in Leeds) and his father was called Charles Atha (b. before 1731).
I hope this is of some help to you, but I have an Atha friend in Georgia who hasn't found a link with me yet. There do seem to be a lot more Atha's in the States than there are in England so there may have been a mass exodus at some point. It would be interesting to find out why.