Without the inhalation of water and some circulation present in the victim, the diatoms will not be able to enter the alveolar system and blood stream making it difficult to extract a reliable sample. Another issue with the use of diatoms in order to provide evidential support is that diatoms can also be found on clothes, in food and drink, or air. In a study conducted by Spitz and Schneider in 1964, 500 cubic meters of air was filtered for three days in April and there was between 662 and 1564 individual diatoms present on the filtrate.[7] Because the body can preserve these microscopic algae, the presence of diatoms may not only be on a victim or suspect through their relation to a crime scene, which affects the reliability of the results collected from a scene.