The director of environmental quality shall establish a hazardous materials emergency response and recovery organizational unit in the department to function as the scientific support, health, safety and environmental element of the hazardous materials emergency management program pursuant to section 49-123. On request from the department of health services and at the direction of the director of environmental quality, the unit shall perform appropriate soil and water sampling for toxic and other harmful effects on the public health and the environment in areas that have been affected by a chemical or other toxic fire.