I try to use organic cotton in my products as much as possible. All of my cloth pads (aka mama pads) are made with Bamboo/Organic Cotton blends. My cloth baby wipes / family cloth is made from 55% hemp/ 45% organic cotton fleece.
But since you don't eat it why should it matter?
I found a great site : The Pesticide Action Network of North America - PANNA
According to PANNA conventional cotton is the most pesticide intensive crop grown:
Conventionally grown cotton uses more insecticides than any other single
crop and epitomizes the worst effects of chemically dependent agriculture.
Each year cotton producers around the world use nearly $2.6 billion worth of
pesticides -- more than 10% of the world's pesticides and nearly 25% of the
Cotton growers typically use many of the most hazardous
pesticides on the market including aldicarb, phorate, methamidophos and
endosulfan. Cotton pesticides are often broad spectrum organophosphates--pesticides originally developed as toxic nerve agents during World War II--and carbamate pesticides.
Pesticides used on cotton-even when used according to instructions-harm people, wildlife and the environment.
These pesticides can poison farm workers, drift into
neighboring communities, contaminate ground and surface water and kill
beneficial insects and soil micro-organisms.
Obviously it's not always possible to get organic cotton but I do whenever I can. Our family cloth/ baby wipes are all made with 55% hemp/ 45% organic cotton and the bamboo blends I use in our Domino Pads all have organic cotton as the second component (after bamboo).