Is there a link between pesticides and developing lupus ?

YES: Yes. Pesticides and other toxic chemicals are a major cause of autoimmune diseases including lupus- see http://www.Medpagetoday.Com/rheumatology/arthritis/24625 the autoimmune epidemic by donna jackson nakazawa is a great book on the subject. If you have lupus then minimizing exposure to toxins and working with a holistic doctor to safely detoxify would be wise.