If you're deciding what to plant in your small spaces, you might want to refer to this guide, published by Food News as they tell you which fruits and vegetables are most loaded with pesticides. I've put in the top 20 here, but visit the site for the rest of the list.

FoodNews: Shopper's Guide to Pesticides
The Full List: 47 Fruits & Veggies
RANK FRUIT OR VEGGIE SCORE
1 (worst) Peach 100 (highest pesticide load)
2 Apple 93
3 Sweet Bell Pepper 83
4 Celery 82
5 Nectarine 81
6 Strawberries 80
7 Cherries 73
8 Kale 69
9 Lettuce 67
10 Grapes - Imported 66
11 Carrot 63
12 Pear 63
13 Collard Greens 60
14 Spinach 58
15 Potato 56
16 Green Beans 53
17 Summer Squash 53
18 Pepper 51
19 Cucumber 50
20 Raspberries 46