Pyroclastic debris: This is a general term for fragmental material ejected from a volcano during an eruption. It includes ash, pumice, cinders, and volcanic bombs. Ash and dust: These are fine-grained particles of volcanic rock and glass that can be carried long distances by wind. Nitrogen compounds: Nitrogen is a common gas released by volcanoes, and it can react with other elements in the atmosphere to form compounds such as ammonia and nitrogen oxides. Sulphur compounds: Sulphur dioxide (SO2) is one of the main gases released by volcanoes. It can irritate the respiratory system and contribute to acid rain. Other sulphur compounds, such as hydrogen sulphide (H2S), can also be released in smaller amounts. All of the above (1, 2, 3, and 4) are products of volcanic eruptions.