You asked about your latex mattress - it depends on what else is in it besides latex. It's very difficult and very expensive to get pure natural latex. Most latex is a blend of natural latex and chemicals. You would need to check with the manufacturer to see what chemicals are used. And even a latex mattress needs to be fireproofed according to law so unless it's covered in wool for fire-proofing, there are toxic chemical fire retardants used.
Foam is polyurethane foam and this is toxic. Most cheap mattresses do have polyurethane foam.
Here is an article on co-sleeping and toxic mattresses:Co-Sleeping and Toxic Mattreses
Organic cotton is the safest material for a mattress. And wool and natural latex and if you can find natural latex that is really pure. One important thing to ask is what do they use to make it fire retardants since manufacturers are required by law to make them fire retardant and most use toxic chemicals.
Here are more articles. They're about crib mattresses but this info is pertinent to adult and child mattresses. The only difference is that crib mattresses usually have vinyl and child and adult mattresses don't have the vinyl but they do usually have the foam and fire retardants.http://www.healthychild.com/toxic-sleep/