Breathe better. The problem with paints is that they are made up of tons of chemicals that are not healthy for us or our environment. Disposal problems aside, the biggest issue for homeowners is actually breathing in VOC's (volatile organic compounds) during and after painting as the freshly painted walls off-gas for days and weeks.
Fortunately there are a number of Low-VOC paints available that off-gas less and are less harmful for you and the environment. Benjamin Moore's Pristine Eco-Spec line is one of them. It contains less than 10 grams of VOC's per liter (to qualify as low VOC you must have less than 200 grams per liter).
Eco-Spec is a low odor, low VOC, 100% acrylic latex paint that comes in flat, egg-shell and semi gloss. You buy Eco-Spec as a base white and then get it mixed to color, which includes off-whites and neutrals, but does not include the darker and brighter colors.
The price is roughly 10%-20% more than normal paint but is highly recommended for interior residential finishes, especially around children. MGR