Lesson 9

How can you measure radon in

water?

Slide 9-2

Radon in water

• Tap water from underground source may be a concern

• Test water to determine radon level

• Tap water from surface source usually not a concern

Slide 9-3

Risk from radon in water

• Radon released into the air

• Radon remaining in water

Slide 9-4

Result of radon in water

168 cancer deaths/year

Lung cancer,

89%Stomach cancer,

11%

Smoking increases the risk of lung cancer associated with radon

Slide 9-5

CT Department of Public Health Guidelines

For private wells

Mitigate if average (of 2 or more samples in 1 year) is

5,000 pCi/L or more

Slide 9-6

Taking a water samplePrinciples

• Sample carefully– Sample fresh water directly from well– Avoid exposure to open air when you collect

and transport sample

• Analyze promptly– Ensure that the lab analyzes the sample within

4-6 hours of its collection– Use a lab approved by the Connecticut

Department of Public Health www.dph.state.ct.us/BRS/EHS/Radon/Documents/ LABLIST.pdf

Slide 9-7

Sampling methods

• Direct syringe • Filled vial

Slide 9-8

Preparation for both methods

• Remove aerator if present• Select a sample point before

water passes through any water treatment device – Example: Outside hose connection

• Run cold water from faucet for enough time to collect water directly from the well– Usually about 20-25 minutes– Discard water that has been sitting

in well casing, pipes, or pressure tank

Sample before • Hot water

heater• Water

softener• Holding tank

Slide 9-9

Direct syringe method

• Equipment– A 10 cm3 syringe– 2 glass vials containing

mineral oil

Radon dissolves in mineral oil, which prevents gas from escaping into air in the vial

Slide 9-10

Direct syringe procedure

• Use a short hose to connect a funnel to faucet• Run water to fill the hose and overflow funnel• Insert syringe below water surface in funnel• Collect a 10 cm3 sample• Place syringe tip below mineral oil and gently

inject sample into vial• Repeat, taking second sample from same

source

Slide 9-11

Filled vial method

• Equipment– 2 40 mL glass vials with screw caps that seal tightly

• Procedures– Be careful to avoid air bubbles– Fill vials using procedure A or B

Slide 9-12

Filled vial procedures

Procedure A• Fill vial very

slowly from faucet

• Allow vial to overflow

• Cap quickly• Repeat with

another vial– Take second

sample from same source

Procedure B• Hold bowl close to

faucet and run water until bowl overflows

• Submerge vial in bowl and cap vial while water is running

• Repeat with another vial– Take second

sample from same source

Slide 9-13

After collection

• Check for air bubbles– Turn vials upside downs– If you see bubbles,

repeat collection procedure until sample contains no bubbles

• Record – Volume– Date and time of

collection

• Pack vials carefully

• Mail to lab the same day– Send via quick method

so samples arrive within 3 days

– Lab should analyze samples the same day they arrive

Slide 9-14

Pros and cons

Direct syringePro

More accurateCon

May be difficult to ship

Filled vialCon

Requires great care to avoid bubbles

Pro Easier to ship

Slide 9-15

Questions?

Slide 9-16

Summary

• Underground water sources may contain dangerous levels of radon

• Radon can cause lung, stomach, and other cancers

• CT DPH guidelines: mitigate if average level is 5,000 pCi/L or more

Slide 9-17

Summary

Principles of taking water samples1. Sample carefully

• Get fresh water direct from well• Avoid exposing sample to air

2. Analyze samples promptly

Slide 9-18

Summary

• Direct syringe method

• Filled vial