title: Concentrations of polychlorinated dibenzo-p-dioxins in processed ball clay from the United States.
abstract: Processed ball clays commonly used by the ceramic art industry in the United States were collected from retail suppliers and analyzed for the presence and concentration of the 2,3,7,8-Cl substituted polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/PCDFs). The average PCDD toxic equivalent (TEQ) concentrations of these processed ball clays was approximately 800 pg/g (TEQ-WHO) with characteristic congener profiles and isomer distributions similar to patterns of previously analyzed raw and processed ball clays. The PCDF concentrations were below the average limit of detection (LOD) of 0.5 pg/g. Correlation analyses reveal no significant relationship between total organic carbon (TOC) and either individual, homologues, and total tetra-through octa-chlorinated PCDD congeners, or TEQ concentrations of the processed ball clays. The results are consistent with earlier studies on levels of PCDDs in ball clays. Data from earlier studies indicated that dioxins may be released to the environment during the processing of raw clay or the firing process used in commercial ceramic facilities. The presence of dioxin in the clays also raises concerns about potential occupational exposure for individuals involved in the mining/processing of ball clay, ceramics manufacturing and ceramic artwork.
authors.affiliation: United States Environmental Protection Agency, Office of Prevention, Pesticides, and Toxic Substances, Environmental Chemistry Laboratory, Building 1105, John C. Stennis Space Center, MS 39529, USA. ferrario.joseph@epa.gov
authors.forename: Joseph
authors.initials: J
authors.lastname: Ferrario
authors.forename: Christian
authors.initials: C
authors.lastname: Byrne
authors.forename: John
authors.initials: J
authors.lastname: Schaum
mesh_terms: D000538:Aluminum Silicates / Q000032:analysis* / Q000737:chemistry; D001572:Benzofurans / Q000032:analysis*; D002244:Carbon / Q000032:analysis / Q000737:chemistry; D002516:Ceramics; D000077215:Clay; D007220:Industrial Waste; D007536:Isomerism; D009930:Organic Chemicals / Q000032:analysis / Q000737:chemistry; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000032:analysis; D012989:Soil Pollutants / Q000032:analysis*; D014481:United States
chemical_list: D000538:Aluminum Silicates; D001572:Benzofurans; D007220:Industrial Waste; D009930:Organic Chemicals; D000072317:Polychlorinated Dibenzodioxins; D012989:Soil Pollutants; D002244:Carbon; D000077215:Clay