Los Angeles County, CA

ZIP 91008

In ZIP 91008, 7 of the 12 things we check have at least one part graded D or F.

• Drinking water: Monrovia-City, Water Dept. has 2 contaminants at or over an EPA legal limit; 14 contaminants are above health goals, led by pfhxs at 1.4× California Notification Level.
• Nearest Superfund site: San Gabriel Valley (area 2), 4.7 miles away (3 within 10 miles).
• Largest share of modeled toxic air from industry: Sterigenics-Ontario Facility (22%), mostly ethylene oxide.
• Fine particles (PM2.5) average 10.8 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 250,208 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 91008

• Superfund sites nearbyF
• Factories and industrial sitesD to F
• Oil and gas wellsA to C
• Parks and nature nearbyA to B
• Air qualityF
• Drinking water qualityD to F
• Pesticide useB to C
• Neighborhood health statusB to C
• Past wildfire impactsD to F
• Past flood impactsA
• Noise levelsA to D
• Radiation signalsC to D

Based on 3 census tracts · compiled October 25, 2026 · how each grade works and its sources

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