Why are all of our art supplies toxic?

Being an artist and environmentalist, I feel a major conflict in my values as I wash my oil paint brushes with turpentine, paint on unsustainable wood panels and rolls of canvas and use toxic paints. I’ve been hesitant in the past to abandon my oils because I haven’t yet seen anything else that has the same intensity and richness and can capture what I need to express. I’ve done much research on making and using non-toxic, earth based paints and materials and have been surprised at the lack of information online or teachers on the subject.
My latest series of abstract oil paintings, “Laying on the Earth”, literally incorporates the earth into my paintings as well as being inspired by the patterns, textures and energy of the earth. I mixed wood ash, soils from the area, marble dust, granite dust and different sands into my gesso which I applied and then painted with oils. I would like to go deeper and get closer to the earth in the actual process and experiment with different soils, plants, seaweeds, flowers and berries as my pigment and play around with different oils or liquids as a binder (walnut, flax, water, etc.). I would also like to try different surfaces (hemp, organic cotton, old sheets or curtains from thrift stores, driftwood, etc.) and experiment with different “brushes” such as twigs, pine needles, leaves, my fingers, etc. Even experiment with different natural glues as a primer (as opposed to toxic gesso). My self- assigned goal is to start on this journey of experimentation and let you all know what I find out. Please add to my blog if you have any more info to add on the subject.