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Potential Risks Associated with Leaching of Organic Contaminants and Endocrine Disruptors from Plastic Piping Materials Glen R. Boyd

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Presentation on theme: "Potential Risks Associated with Leaching of Organic Contaminants and Endocrine Disruptors from Plastic Piping Materials Glen R. Boyd"— Presentation transcript:

1 Potential Risks Associated with Leaching of Organic Contaminants and Endocrine Disruptors from Plastic Piping Materials Glen R. Boyd (glen.boyd@hdrinc.com)glen.boyd@hdrinc.com Gregory L. Pierson HDR Engineering, Inc. Ronald J. English Seattle Public Schools Pacific Northwest Section AWWA Vancouver, WA May 2, 2008 500 108 th Ave NE, Ste 1200 Bellevue, WA 98004

2 Outline Background Objective Current Knowledge & Perceptions Typical Plastic Plumbing in Schools Safeguards – Industry Standards Conclusions

3 Background - Seattle Public Schools Number of students: 47,000 No. of schools & admin facilities: 102 Number of schools >40 years old: 60% (plumbed primarily with galvanized steel piping and moderately tuberculated)

4 Background - What were the Issues? Parents inquiries in late 2003 – Unpleasant appearance of water in several older schools – Rusty water  health concern – Pb exposure – Other WQ concerns Seattle Schools previously addressed WQ issues in 1990

5 Background - Phase 1 Testing in 2004 Objective and Approach – Assess water quality in Seattle Public Schools – Sampled 3,000+ sources (primarily fountains) – Analyzed for Pb plus Cd, Zn, Cu, Fe, turb, color, and colif bact Results – 19% first-draw 250-mL samples Pb >20  g/L (EPA guideline for schools) – Some fountains exhibited Pb >1000  g/L Outcome – Seattle School Board Policy – Pb must be  10  g/L in first-draw 250-mL sample prior to service – Implement District-wide Mitigation Program

6 Background - Sources of Pb are Numerous Old galvanized piping in laterals, risers and service lines End-use connective piping 50:50 Sn:Pb solder Brass valves & other components Bubbler heads Kitchen and classroom faucets

7 Background – Upgrade Plumbing Old end-use connective piping New plastic tubing and components Overall Mitigation Program Goal – Meet School Board Policy Pb  10  g/L in all first-draw 250-mL samples

8 Background – Parents’ Concern Metal parts – release of Pb and other metals Plastic parts – potential release of organics (e.g., EDCs and other) Water Quality Oversight Committee – Precautionary Principle Fully evaluate alternatives – prevent or minimize harm

9 Objective Assess potential risks associated with using plastics in place of metals in schools – Review available literature – Review industry standards

10 Current Knowledge – Endocrine (Hormone) System Hormones are synthesized and secreted by glands into blood stream Regulation of biological processes – Function of reproductive system – Brain and nervous system – Metabolism

11 Current Knowledge – Endocrine Disrupting Compounds (EDCs) Endocrine Disruptor – an exogenous substance or mixture that alters functions of the endocrine system and consequently causes adverse health effects Dose-Response Relationships – EDCs mimic or antagonize natural hormones – Low-dose effects – controversial – Timing of exposure is critical Trussel, R. 2001. JAWWA 93(2):58-65 WHO. 2002. Global Assessment of EDCs.

12 Current Perception – Why is the Public Increasingly Concerned? “… study examined nine pesticides … used on cornfields in the midwestern United States.” “Larvae were treated by immersion with 0.1 ppb each atrazine, S -metolachlor, alachlor, nicosulfuron, cyfluthrin, - cyhalothrin, tebupirimphos, metalaxyl, or propiconizole.” “Seventy percent of the animals exposed to the nine-compound mixture were unable to sit upright.” T.B. Hayes et al. 2006. Env. Health Perspect, Vol. 114, S-1, Apr.

13 Current Perception – Why is the Public Increasingly Concerned? Meds lurk in drinking water AP probe found traces of meds in water supplies of 41 million Americans Associated Press – March 9, 2008 “A vast array of pharmaceuticals — including antibiotics, anti- convulsants, mood stabilizers and sex hormones — have been found in the drinking water supplies of at least 41 million Americans, an Associated Press investigation shows….” Ref: Env. Health Persp., Oct 2000.

14 Current Perception – Why is the Public Increasingly Concerned? Containers made with bisphenol A chemical linked to health risks Associated Press – April 18, 2008 “Hard-plastic Nalgene water bottles made with bisphenol A will be pulled from stores over the next few months because of growing consumer concern over whether the chemical poses a health risk.” Nalgene to phase out hard-plastic bottles

15 Typical Plastic Plumbing - Seattle Public Schools Plastic Pipe or Component DescriptionCertification Sch 80 PVC Connective Piping ⅛ - ¼” PVC and CPVC NSF 61 Sch 80 PVC Fittings ⅜ - ½” PVC and CPVC NSF 61 Polyethylene (PE) flexible tubing ⅜” OD (125 psi, 150°F) NSF 61 Polypropylene (PP) fittings Fittings for food, any size (212°F) NSF 51

16 Plastic Materials – Polymeric Chains Polyvinyl chloride (PVC) and chlorinated PVC (CPVC) Polyethylene (PE) Ref: www.wikipedia.org Polypropylene (PP)

17 Common Chemical Additives – Manufacturing of Plastics Phthalates – plasticizers improve flexibility, workability, softness, and elongation properties Di-(2-ethlyhexyl)-phthalates (DEHP) Diisononyl phthalate (DINP) Phenolics – stabilizer or antioxidant for material durability Ref: www.lineone.net Bisphenol A Organotins – heat and UV-oxidation resistance stabilizers used in rigid and flexible PVC and other plastics Dibutyltin Dimethyltin R 2 SnX 2

18 Leaching of Chemical Additives in Drinking Water Chemical Additive Reported Leaching Levels in Distributed Water (µg/L) Reference Phthalates USA0.05-1.1 WHO (2003) Japan1.2-1.8 Phenolics Japan>0.94 Hu et al (2002) Chlorinated BPA v. reactive Organotins New PVC0.028-0.053 Sadiki et al (1996; 1999) Dwellings<0.0005 WHO (2003) – World Health Organization; Hu et al (2002) Environ Sci Technol ; Sadiki et al (1996; 1999) Chemosphere.

19 Safeguards – Industry Standards NSF/ANSI Standards and Certification Program – applies to all direct and indirect drinking water additives NSF International (lead), AwwaRF, ASDWA, CSHEM, and AWWA NSF Standard 61 Minimum health effects requirements for chemical contaminants indirectly imparted from materials used in drinking water systems

20 Safeguards – Industry Standards Table 2 - Material-specific Analyses   Material Type Required Analyses Polyvinyl chloride (PVC) and chlorinated polyvinyl chloride (CPVC) Phenolics 1, regulated metals 2, VOCs, tin 4, antimony 5, residual vinyl chloride monomer (RVCM) 6 Polyvinyl chloride (flexible)Phenolics 1, regulated metals 2, VOCs, tin 4, RVCM 6, phthalates 7, zinc 8 Polybutylene (PB)VOCs, regulated metals 2, phenolics 1 Polyethylene (PE)VOCs, regulated metals 2, phenolics 1 Polypropylene (PP)VOCs, regulated metals 2, phenolics 1 1 Analysis in accordance with EPA Method 420.2 or other as indicated in NSF/ANSI 61 – 2003e, section B.7.4. 2 Antimony, arsenic, barium, beryllium, cadmium, chromium, copper, lead, mercury, selenium, thallium 4 Required when tin-based stabilizers are used. 5 Required when antimony-based stabilizers are used. 6 Analysis of residual vinyl chloride monomer in PVC and CPVC products using GC-FID by analyzing 0.5 g of plastic material to method sensitivity of 0.5 ppm (mg/kg). 7 Required when phthalate ester plasticizers are used. Analysis shall be for the specific phthalate ester(s) used in the formulation. 8 Required when zinc-based stabilizers are used.   Based on Table 3.1 – Material-specific analyses, NSF/ANSI 61-2003e, page 7.

21 Safeguards – Industry Standards Table 5 - NSF International drinking water criteria (not externally peer reviewed)   SubstanceCAS# Total Allowable Concentration (TAC), mg/L Bisphenol A80-05-70.2 Butyltin compounds (mono- and di- only) N/A0.02 (total) Diisononyl phthalate28553-12-00.05 Isophthalic acid121-91-50.01 Terephthalic acid100-21-00.01   Derived from Table E1, NSF/ANSI Standard 61-2003e, page E3. New products must satisfy “risk assessment” based criteria (NSF/ANSI Standard 61-2003e) as summarized in Table 5.

22 Expert Opinion National Academy of Sciences, Water Science and Technology Board – Public Water Supply Distribution Systems: Assessing and Reducing Risks (2005) “A committee … will conduct a study of water quality issues associated with public water supply distribution systems and their potential risks to consumers.” “The study will consider …… cross connections and backflow, pressure transients, nitrification, permeation and leaching, repair and replacement of water mains, aging infrastructure, and microbial growth.” “… it is currently believed that leaching is a relatively low priority relative to other distribution system problems.” http://www4.nas.edu/webcr.nsf/ProjectScopeDisplay/WSTB-U-04-06-A?OpenDocument http://www.nap.edu/books/0309096286/html/R1.html

23 Additional Information Glen Boyd HDR Engineering, Inc. Bellevue, WA 425-450-6391 glen.boyd@hdrinc.com


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