CRD Regional Water Supply Commission Meeting, July 17, Lab Reporting of Dioxins & Furans What are Dioxins & Furans? Two families of similar chemical compounds containing chlorine atoms on a carbon ring Dioxins in Environment Widespread in environment With the advanced lab detection methods now used they are found in air, water, plants, soil, food, etc. WHO Tolerable Daily Intake is 1 to 4 pg/kg/d for adults

CRD Regional Water Supply Commission Meeting, July 17, Lab Reporting of Dioxins & Furans Sources combustion sources: incinerators, residential wood burning, automobiles, tire incineration, coal fired utilities, forest fires pulp and paper mill effluents, organochemical production, metal smelters and refiners, other industrial processes, seepage from landfill sites, atmospheric deposition

CRD Regional Water Supply Commission Meeting, July 17, Lab Reporting of Dioxins & Furans Reporting List of Dioxins Typically monitor 210 dioxin and furan compounds Report total values and the 17 individual compounds considered most toxic

CRD Regional Water Supply Commission Meeting, July 17, Lab Reporting of Dioxins & Furans Units of Measure in Soil Expressed as picograms per gram (pg/g) Picogram is grams or one-trillionth of a gram Parts per trillion Units of Measure in Water Expressed as picograms per Litre (pg/L) Parts per quadrillion

CRD Regional Water Supply Commission Meeting, July 17, Lab Reporting of Dioxins & Furans Results Reported as ‘ND’ “ND’ means “Not detected’ w No signal or peak was observed for that compound Detection limit is concentration that would have to be present to give an observable signal ND with a DL of 0.11 pg/g means that compound was not present at a concentration of 0.11 pg/g or higher. It could be less than that, e.g., 0.08 or even zero.

CRD Regional Water Supply Commission Meeting, July 17, PCDD/PCDF Analysis Report

CRD Regional Water Supply Commission Meeting, July 17, PCDD/PCDF Analysis Report (cont’d)

CRD Regional Water Supply Commission Meeting, July 17, Lab Reporting of Dioxins & Furans Toxicity Equivalents (TEQ)s System of converting concentration numbers to a single result Combines concentration data and toxicity to give a “Toxic Equivalents” or TEQ. Toxicity of individual dioxins and furans varies Several conventions to calculate TEQs

CRD Regional Water Supply Commission Meeting, July 17, Lab Reporting of Dioxins & Furans Toxicity Equivalence (TEQs) International Toxicity Equivalency Factors (I- TEFs) assigned to the 17 toxic compounds Most common I-TEFs are NATO and WHO I-TEFs vary from 1.0 for 2,3,7,8-TCDD to (NATO) or (WHO) for OCDD/OCDF For each compound, multiply the concentration by its I-TEF; then sum to get TEQ.

CRD Regional Water Supply Commission Meeting, July 17, Lab Reporting of Dioxins & Furans Conventions for ReportingTEQs when Results are ND If a compound is ND, options include w ND = 0 (multiply I-TEF by zero) w ND = 1/2 detection limit (multiply I-TEF by 1/2 DL) In BC, the most common system is NATO and report two TEQ results

CRD Regional Water Supply Commission Meeting, July 17, Lab Reporting of Dioxins & Furans Procedural Blanks Procedural blanks are samples analyzed in same run but no soil or water w Tests whether or not dioxins are present in analytical system Reporting Results of Procedural Blanks Results reported in same way as for test samples Typical TEQs for blanks are pg/g where (ND=1/2DL)

CRD Regional Water Supply Commission Meeting, July 17, Lab Reporting of Dioxins & Furans Comparing Blanks to Real Samples TEQ results for real samples that are the same as or less than the blank can be interpreted as: “Dioxins not detected”