Many allergens such as dust or pollen are airborne particles. This might occur if the cleaner were full of dust and debris. Disks of space dust (debris disks) surround many stars. Tooth anatomy suggests consumption of gritty foods covered in particulates such as dust or dirt. The eyes may water in response to dry air, dust, or airborne allergens. Spring is extremely dry and prone to dust storms. The more dust, the darker the surface. Risk factors include exposure to tobacco smoke, dust, and other air pollutants. Risk factors include exposure to tobacco smoke, dust, and other air pollution. There are local names for winds associated with sand and dust storms. Airborne soils originate with windy conditions and road dust. They also enjoy taking dust and sand baths. Contaminants from these two categories lead to elevated amounts of toxins in street dust. Sunlight scattered by interplanetary dust causes this phenomenon. She warns Asriel, then spies on his lecture about Dust, mysterious elementary particles.