I did some research to find out if eggplant was a vegetable that you need to buy organic.
First, I turned to What's on my food? which is a website with a ton of specific information on the types of pesticides that are found on each category food. They have an extensive list of foods--everything from almonds to watermelon. The website has symbols listed next to each pesticide so you can easily tell if it is a carcinogen, hormone disruptor, neurotoxin, developmental or reproductive toxin or bee toxin.
If you look up asparagus, for example--a vegetable that is safe to buy non organic because it is hardly sprayed--you see that while 9 pesticide residues were found they often were only found in 3.3% of the asparagus tested. Looking up eggplant, it looks like only traces from 18 pesticide residues were found (which is actually pretty low compared to apples which have traces of 42 pesticides on them--Thiabendazole is a known carcinogen found on 87% of apples.) Still, when you read this study out of Harvard it makes you realize that these these pesticides are having a real impact and maybe it is better to make the extra effort to buy organic...
This is from the What's on my food? website...
"A new study out of Harvard shows that even tiny, allowable amounts of a common pesticide class can have dramatic effects on brain chemistry. Organophosphate insecticides (OP’s) are among the most widely used pesticides in the U.S. & have long been known to be particularly toxic for children. This is the first study to examine their effects across a representative population with average levels of exposure. Finding :: Kids with above-average pesticide exposures are 2x as likely to have ADHD." 1
Another GREAT resource that is quite simple is the Environmental Working Group (EWG) Shopper's Guide to Pesticides in Produce. According to EWG, eggplant are on the clean 15 meaning that eggplant is a produce that was among the lowest in pesticides--quite close to asparagus and right next to avocado--two of my favorite vegetables.
I recommend looking up any produce on BOTH of these websites that you are eating every day so that you can make an informed decision about whether to buy conventional or spring for the higher priced organic version. And don't be mislead by the price tag. They sell organic produce at Costco at affordable prices and conventional produce at Whole Foods.
This is especially important for children and people with chronic health issues who are most at risk at being affected by the toxins in pesticides. EWG clearly says "The health benefits of a diet rich in fruits and vegetables outweighs he risks of pesticide exposure." 2 So don't be afraid--just be informed.
It looks like eggplant is one of the safer vegetables to buy conventional--but I would still buy the organic if given the choice.