Particulates, alternatively referred to as particulate matter or fine particles, are tiny particles of solid or liquid suspended in a gas or liquid. In contrast, aerosol refers to particles and the gas together. Sources of particulate matter can be man made or natural. Particulate Matter-(Water quality) In water pollution, particulates can either be in a solid or dissolved state. Solid particulates can be removed by filters or settle from the water, and is referred to as insoluble particulate matter. Whereas, dissolved particulate matter in water is collected by allowing the water to evaporate, leaving behind the dissolved particulate matter. Salt is an example of dissolved particulate matter. Some particulates occur naturally, originating from volcanoes, dust storms, forest and grassland fires, living vegetation, and sea spray.