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– Avoid air bubbles in the sample vial

• 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 techniques• Syringe • Immersion

Slide 9-8

Preparation for both techniques

• Remove aerator if present• Select a sample point before water

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

• Purge water that has been sitting in pipes and tanks– Run cold water from faucet for enough

time to collect water directly from the well

– Usually about 20-25 minutes• If sampling outside

– Do not let purge water puddle in the yard – Resident can assist purging by running

water inside the home

Sample before • Hot water

heater• Water

softener• Holding tank

Slide 9-9

Syringe technique• Equipment

– A 20-mL hypodermic syringe

– 2 glass vials• With TFE or foil-lined caps

that seal tightly• Containing “liquid

scintillation cocktail” – A sampling funnel– Tubing or hose

Slide 9-10

Syringe technique procedure

• Use a short hose to connect the funnel to faucet– Run water to fill the hose and overflow funnel

• Slow the water flow and insert syringe below water surface in funnel– Slowly collect a 12-15 mL sample– Rinse and repeat a few times

• Invert syringe to eject any air bubbles and retain 10 mL of water– Place syringe tip below “liquid scintillation cocktail” and

gently inject 10 mL sample into vial– Slowly withdraw syringe

• Tightly cap the vial• Repeat, taking second sample from same source

Slide 9-11

Immersion technique

• Equipment– 2 40-mL glass vials with TFE or foil-lined caps

that seal tightly– Hose or tubing– Clean 5-gallon bucket or similar container

Slide 9-12

Immersion technique procedure

• Attach one end of hose or tubing to spigot, and place other end in bucket

• Fill bucket about half full of water• Slow the flow rate and submerge vial in

bucket– Place vial below hose, where fresh

water is entering bucket• Let vial fill with fresh water for about 20

seconds• Cap vial while it is still submerged and

water is running• Repeat with another vial, taking second

sample from same source

Be careful to avoid air bubbles

Slide 9-13

After collection• Check for air bubbles

– Turn vials upside down– If you see bubbles,

repeat collection procedure until sample contains no bubbles

• Record – Sample name/ID

(usually address)– 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

Activity• Practice the two techniques• Note any problems using the

techniques

Slide 9-15

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

See handout 9-1

Slide 9-16

SummaryPrinciples of taking water samples

1. Sample carefully• Get fresh water direct from well• Avoid exposure to open air during

collection and transport• Avoid air bubbles in sample

2. Analyze samples promptly

Slide 9-17

Summary• Syringe technique • Immersion

technique

Slide 9-18

Questions

Slide 9-19

Check your understanding

• See handout 9-2