Arsenic in Drinking Water
Arsenic is a naturally occurring carcinogen found in groundwater across the US. Long-term exposure causes cancer, cardiovascular disease, and developmental problems in children.
What is Arsenic?
Arsenic is a naturally occurring element found in rocks and soil. It dissolves into groundwater, especially in areas with arsenic-rich geological formations. The Southwest US has the highest natural levels.
Silent Threat: Arsenic is colorless, tasteless, and odorless. Testing is the only way to know if it's present. An estimated 2.1 million Americans are exposed to arsenic above EPA limits.
Health Effects
Long-Term Exposure Risks
- • Bladder, lung, and skin cancer
- • Cardiovascular disease and high blood pressure
- • Type 2 diabetes
- • Skin lesions and discoloration
- • Peripheral neuropathy (nerve damage)
- • Liver and kidney damage
- • Reduced IQ in children
EPA Maximum Contaminant Level
EPA lowered limit from 50 ppb to 10 ppb in 2006. Many health advocates argue it should be lower (around 3 ppb) as studies show increased cancer risk at levels as low as 5 ppb.
Most Affected US Regions
High-Risk Cities
- • Phoenix & Tucson, Arizona
- • Albuquerque, New Mexico
- • San Antonio, Texas
- • Las Vegas, Nevada
- • Parts of New England
High-Risk Regions
- • Southwest US (highest levels)
- • Midwest agricultural areas
- • New England
- • Parts of Alaska
Note: Groundwater sources are more affected than surface water. Private wells in arsenic-rich areas often have dangerous levels.
Testing for Arsenic
When to Test
- • Use groundwater or private well
- • Live in Southwest or high-risk region
- • Planning pregnancy
- • Purchasing home with well
- • Skin discoloration or lesions
Testing Cost: $20-100
Contact EPA-certified labs or local health department.
How to Remove Arsenic
Effective Methods
1. Reverse Osmosis
95-98% reduction - Most effective and reliable
2. Anion Exchange
90-95% reduction - Professional installation needed
3. Activated Alumina
85-95% reduction - Requires pH adjustment
Warning: Standard carbon filters do NOT remove arsenic. Boiling water concentrates it - never use for removal.