Table 4.

Contam table data fields: the contaminants table, “contain”, served as an addendum to the material table. The primary key was comprised of the publication DOI and MaterialID of the contaminated material. The field contaminant listed the name of the contaminating substance. ContamAmount, ContamUnit, and ContamMethod held the information on the scale of the contaminant and the way the contamination was measured. This allowed for a material to have any number of contaminants, each detailed in its own row

Contam (contaminants) table	Description
ContamID	Unique identifier for the contaminant data point
material_MaterialID	Reference to material ID of the material in which this contaminant was found
material_publication_DOI	Reference to DOI of source publication
Contaminant	Chemical identity of the contaminant
ContamAmount	Measured numerical amount of the contaminant
ContamUnit	Units of measurement of contaminant (e.g., %, units of mass per volume)
ContamMethod	Analytical method to identify and measure the contaminant (e.g., ICP-MS, etc.)