Simple steps to start collecting.
Follow the simple instructions below
to gather the materials you want
tested. Attend a local gathering
for additional training, see events.
Collect & Submit
Drop your samples off at the nearest
University of Arizona Cooperative
Extension office for transport to
Dr. Ramirez-Andreotta’s Integrated
Environmental Science and Health
Risk Laboratory analysis.
University of Arizona researchers
will run extensive tests to determine
the concentration of potential
contaminants. If you are interested
in preparing your own samples
in the laboratory, please contact
Dr. Ramirez-Andreotta directly.
Gather with community members
and researchers to discuss results
that will help improve our
It's easy to participate and stay informed about the environment where you live. Just subscribe to our mailing list.
Select what you want tested.
Soil from garden
- Select 6 spots to sample in your garden in a roughly grid-like pattern.
- Using the hand trowel provided, loosen the top 6 inches (the approximate length of the hand trowel blade) of each of the 6 soil spots.
- At each location, take one full scoop of soil and place it into the 2-gallon bucket labeled Bucket A.
- Mix the six soil samples thoroughly inside the bucket. This process is called sample bulking.
- Fill the bag with the bulked soil sample to the line drawn on the outside of the bag.
- Place the soil paper bag into the 1-gallon Ziploc bag making sure that the label on the brown paper bag is clearly visible.
- Soils should be kept refrigerated until you are ready to drop-off at the County Extension Office.
Soil from yard
You will do the same soil sampling process as you did above for your garden soil, but now for your yard soil. Yard soil means unamended and native soil located on your residential property. Complete steps 1-7 above, note for step 3 you will now use the 2-gallon bucket labeled Bucket B.
Collect Water Samples in late afternoon. Using the water source you use to irrigate your garden. Please do NOT freeze water samples.
- Turn on the water and allow the water to flow for 2-3 minutes. During this you may fill out the labels of the bottles with all the information requested.
- Slow the flow to a small trickle and carefully fill each bottle until water overflows.
- Once full quickly cap each bottle and seal.
- Place the 3 bottles in the 1-gallon Ziploc bag, seal, and store in a refrigerator until you are ready to drop off at the County Extension Office.
Collect a total of 4 plant samples. It is recommended to collect a combination of leafy, root, fruiting, and/or legumes such as: kale, collards, spinach, lettuce, green beans, radish, turnip, peppers, and/or tomatoes.
- Place each vegetable sample in separate Ziploc bag to the line drawn on the outside of the bag and remove all air from bag before sealing.
- Fill out the labels for each vegetable with all the information requested.
- Promptly place the bag in the refrigerator until you are ready to drop off at the County Extension Office.
Please collect a total of two different plant leaf samples. Collect leaves that are parallel to the ground, located on the upper portion of the plant, and do not touch the ground.
- Collect 5 leaves from either a leafy vegetable and/or an ornamental plant in your garden.
- Place each set of 5-leaf samples in separate Ziploc bags and remove all air from bag before sealing.
- Fill out the labels with all the information requested. 4. Promptly place the bag in the refrigerator until you are ready to drop off at the County Extension Office.
Helpful list and locations.
- Garden soil sample in paper bag and then 1-gallon Ziploc bag
- Yard soil sample in paper bag and then 1-gallon Ziploc bag
- 3 water sample bottles in a 1-gallon Ziploc bag
- 4 Vegetable samples individually bagged in separate 1-gallon Ziploc bags
- 2 Leaf samples individually bagged in separate 1-gallon Ziploc bags
- Drop off all samples at the Cooperative Extension Office in your county
Reduce Arsenic Absorption by Vegetables
Test your soils
Before you amend, or grow anything, you should test your soils (once is only needed). Please refer to the Gardenroots Instructional Manual for soil collection methods. Please note that a safe soil arsenic standard for growing vegetables has not been established.
Some garden products may contain arsenic
Pay attention to the garden soil and amendments that you are using.
Iron in soils can reduce the available amount of arsenic
The iron and arsenic come together to form iron arsenate, a form of arsenic that is not well absorbed by vegetables. Please refer to AZ1415.
Place a barrier
You can put an impermeable barrier between the uncontaminated topsoil, and the underlying contaminated soil to reduce mixing, and remind you how deep to till. If you do this, you must provide for bed drainage.
pH is crucial
Keep your soils near the near the neutral zone (6.5-7.5).
The organic matter can help reduce how much a vegetable takes up. Apply at least a layer of organic matter 2 to 3 inches thick on the garden area about 1 to 2 months before planting. Please refer to AZ1435.
Build Containers or raised beds
Construct a container or raised bed using materials and soils low in arsenic and lead. For example, do not use arsenic treated lumber to construct raised beds. Make sure to test the bedding soils before planting.
Replace contaminated soils
This may require technical assistance and guidance from the AZ Department of Environmental Quality.
Arsenic and lead occur naturally in soils. It is impossible to grow plants completely free of arsenic and lead, but there are ways to reduce the amount that is available to, and taken up by your vegetables. Above are important recommended practices.
Reduce Incidental Soil Ingestion and Inhalation
Windy Days = No Gardening
Avoid gardening on windy days.
Avoid eating and drinking while you garden
Soils and dust might get on your food or in your drink, and you could accidental swallow it.
Keep soils moist while gardening to control dust
This will limit the amount of dust you inhale.
Designate a set of clothes and shoes for gardening use only
Keep your gardening clothes and shoes outside, or in a plastic bag outside. Try your best to keep your gardening clothes and shoes out of your home.
Consider wearing a mask in dusty environments.
Wash your hands and all exposed body surfaces after gardening.
Leave your shoes outside
Remove your shoes right before enter your home to avoid tracking soil into your home.
Mop floors with a damp mop, and wipe down surfaces in your home regularly. Change your vacuum bag more often, or upgrade your vacuum to one that has a High-Efficiency Particulate Air (HEPA) filter.
Wash, and then store all your gardening tools outside.
You can greatly reduce your exposure to arsenic from your soil if you follow the suggestions above.
Safe Consumption of Homegrown Vegetables
Reduce Dietary Arsenic and Lead Ingestion
Wash your hands
After gardening, and before vegetable washing.
Once inside your home, wash your vegetables again using a scrub brush to remove remaining soil particles
Look at the shape of your vegetables - some can trap soil particles. For example, soil particles can get trapped in between the flower heads on broccoli, and leafy vegetables have large surface areas where soil can collect.
Mix it up
Eat vegetables from your garden, the grocery store and farmers' market. Eating a mixture of homegrown and store bought can help reduce your potential exposure.
Wash your vegetables before you bring them into the house
This act can reduce the amount of arsenic and lead on your vegetables, and what is transported into your home.
Pare and/or Peel
Pare and/or peel root and tuber crops like carrots, radishes, and potatoes. Make sure you throw the parings and peelings away.
Do not compost unused plant parts, peelings or parings for use in the garden
This act will reduce the recycling of arsenic and lead in your compost.
Arsenic and lead occur naturally in soils. Concentrations of arsenic and lead in soils may be 10 to 100 times greater than concentrations in the vegetables you grown in that soil. Because of this, it is crucial to remove soil particles that stick to your garden crops. Above are important recommended practices.