The answer really is yes, depending on a few variables...
Yes, in that engineered quartz solid surfacing (Caesarstone, Silestone, etc.) emits low VOCs and these products are Greenguard Certified to meet rigorous indoor air quality safety standards. Quartz surfaces are nonporous and prevent the growth of surface mold and bacteria due to the use of quartz as a key ingredient. Quartz products do not need sealing and maintenance like granite or other stone. There is less material waste during manufacturing (quarrying) and fabrication of quartz surfaces. Silestone and Caesarstone both maintain responsible water treatment and reuse in their manufacturing facilities, while also implementing quarry restoration processes and using recycled materials and nontoxic pigments in their product lines.
The questionable parts are the minimal percent of the finished quartz product that is pigment and the small amount of resin used for binding the color to the quartz. It is not clear how environmentally friendly these materials are.
All being considered, quartz is my professional first choice in homes for a kitchen countertop material, and I also recommend it in commercial and medical applications for countertops and other casework applications.