Combined exposures · In-home geology

Radon and arsenic in Iowa homes

Two in-home geologic exposures, estimated for the same Iowa ZIP codes: modeled indoor radon and modeled groundwater arsenic. This page is scoped to Iowa.

IowaData release 2026Modeled inputs

Across parts of Iowa, two separate geologic exposures show up in the same ZIP codes — a modeled likelihood of elevated arsenic in groundwater, and modeled indoor radon. Here is exactly what each measurement is, and the federal reference each is measured against.

How we measure this →

Modeled indoor radonEPA action levelModeled · ZCTA-native

Where the modeled value crosses the line, this area's modeled radon runs above EPA's 4 pCi/L action level — the level at which the EPA recommends taking action to reduce indoor radon. It is an action level, a recommendation to act, never a regulatory limit.

EPA indoor-radon action level — 4 pCi/L. A recommendation to act, not a regulatory limit.

Modeled groundwater arsenicEPA public-water limitModeled likelihood

USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems. Most private wells are federally unregulated, so this is a modeled likelihood, never a measured exceedance.

EPA drinking-water maximum contaminant limit — 10 µg/L. Applies to public systems; private wells are not covered.

What this is — and isn't. These are two exposures estimated for the same place. This page does not claim one causes the other, does not combine them into a single risk number, and does not link either to any health outcome. It reports where both figures are elevated together, and nothing more.

Iowa ZIP codes where both are elevated

The Iowa ZIP codes (ZCTAs) that rank among the highest 10% of US ZIP codes for both modeled exposures. The ranking is national; this list is Iowa only. How each area reads depends on whether its modeled radon actually crosses the 4 pCi/L action level — see the two labels below.

Above action levelmodeled radon crosses 4 pCi/L — the federal-reference sentence rendersElevated (top 10% in the US)in the top 10% of US ZIP codes but below 4 pCi/L — reads as a ranking, not the 4 pCi/L sentence

51002in AltaAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51003in AltonAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51230in AlvordAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51004in AnthonAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51231in ArcherAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51232in AshtonAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51005in AureliaAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
50515in AyrshireAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
50519in BodeAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51234in BoydenAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51007in BronsonAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
50047in CarlisleAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51012in CherokeeAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51014in CleghornAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51016in CorrectionvilleAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51018in CushingAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51019in DanburyAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51333in DickensAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51235in DoonAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
50535in EarlyAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51334in EsthervilleAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51020in GalvaAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51237in GeorgeAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51022in GranvilleAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51343in GreenvilleAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51346in HartleyAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51023in HawardenAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51026in HornickAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51238in HospersAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51239in HullAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51240in InwoodAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51027in IretonAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51347in Lake ParkAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51450in Lake ViewAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51241in LarchwoodAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51029in LarrabeeAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
50554in LaurensAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51030in LawtonAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51033in Linn GroveAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
50561in LyttonAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
50562in MallardAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
50563in MansonAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51035in MarcusAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
50158in MarshalltownAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51036in MauriceAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
50162in MelbourneAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51350in MelvinAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51037in MeridenAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51351in MilfordAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51039in MovilleAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
50568in NewellAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
50208in NewtonAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51354in OcheyedanAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51458in OdeboltAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51044in OtoAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51046in PaullinaAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51047in PetersonAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51048in PiersonAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
50574in PocahontasAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
50575in PomeroyAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
50228in Prairie CityAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51245in PrimgharAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51049in QuimbyAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
50233in RedfieldAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
50576in RembrandtAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51246in Rock RapidsAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51247in Rock ValleyAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
50579in Rockwell CityAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51357in RoyalAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
50237in RunnellsAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51358in RuthvenAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
50583in Sac CityAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51248in SanbornAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51053in SchallerAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51054in Sergeant BluffAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51201in SheldonAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51249in SibleyAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
50585in Sioux RapidsAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51055in SloanAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51056in SmithlandAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
50247in State CenterAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
50588in Storm LakeAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51058in SutherlandAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
51364in TerrilAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
50597in West BendAbove action level
USGS models a high likelihood that groundwater arsenic here exceeds 10 µg/L — the level EPA sets as the limit for public water systems — and this area's modeled radon runs above EPA's 4 pCi/L action level.
50601in AckleyElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50001in AckworthElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50003in AdelElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50510in Albert CityElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50006in AldenElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50420in AlexanderElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50511in AlgonaElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50007in AllemanElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50008in AllertonElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50514in ArmstrongElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
51331in Arnolds ParkElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
51433in AuburnElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50517in BancroftElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
52533in BataviaElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50609in BeamanElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50034in BlairsburgElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50035in BondurantElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50039in BoutonElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
52211in BrooklynElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50424in Buffalo CenterElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50522in BurtElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
51009in CalumetElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50046in CambridgeElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
51011in ChatsworthElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50054in ColfaxElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50055in CollinsElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50056in ColoElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50621in ConradElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50060in CorydonElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50527in CurlewElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50528in CylinderElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50063in Dallas CenterElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50066in DawsonElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50069in De SotoElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
52037in DelmarElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50531in DolliverElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50073in ElkhartElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50536in EmmetsburgElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
51338in EverlyElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50539in FentonElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50540in FondaElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50633in GenevaElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50104in GibsonElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50106in GilmanElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
51342in GraettingerElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50112in GrinnellElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
52221in GuernseyElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50441in HamptonElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50544in HarcourtElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50545in HardyElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
51345in HarrisElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50118in HartfordElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
52232in HartwickElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50546in HavelockElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50120in HaverhillElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
52236in HomesteadElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50123in HumestonElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50124in HuxleyElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50125in IndianolaElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50551in JolleyElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50447in KanawhaElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50134in KelleyElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50135in KelloggElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50139in LaconaElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50451in LakotaElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50452in LatimerElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50141in LaurelElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50556in LedyardElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
52567in LibertyvilleElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50146in LindenElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
51243in Little RockElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50558in LivermoreElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50559in Lone RockElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50560in Lu VerneElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50157in MalcomElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50565in MarathonElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50160in MartensdaleElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50161in MaxwellElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50154in McCallsburgElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50166in MiloElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50167in MinburnElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50168in MingoElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50169in MitchellvilleElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
51556in ModaleElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50170in MonroeElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50567in NemahaElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50201in NevadaElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50206in New ProvidenceElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50211in NorwalkElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50570in OttosenElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50220in PerryElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50225in PleasantvilleElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50669in ReinbeckElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50234in RhodesElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50578in RingstedElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
51051in RodneyElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50236in RolandElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
51052in SalixElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50244in SlaterElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
51360in Spirit LakeElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50239in St. AnthonyElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50590in Swea CityElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
52339in TamaElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50478in ThompsonElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50591in ThorElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50480in TitonkaElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
51466in Wall LakeElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
51365in WallingfordElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
51061in WashtaElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
51366in WebbElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
52355in WebsterElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50680in WellsburgElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50483in WesleyElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50598in WhittemoreElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50271in WilliamsElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50484in WodenElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.
50278in ZearingElevated (top 10% in the US)
This area ranks among the highest 10% of US ZIP codes for both modeled radon and modeled groundwater arsenic.

Coverage & how to read this

Modeled, not measured. Indoor radon uses the Li national ZCTA-level model; groundwater arsenic uses the USGS private-well probability model. Neither is a reading from your home or tap. A ZIP with an unobservable leg is shown as not measured, never as "not impacted." Both references are federal: radon's 4 pCi/L is an action level (a recommendation to act), arsenic's 10 µg/L is the maximum contaminant limit EPA sets for public water systems. A ZIP reaches this list by ranking among the highest 10% of US ZIP codes for each exposure — the ranking is national, and this list is Iowa only. Read the full combined-exposure methodology →

Each ZIP links to its full ZipVitals page. Iowa only — the national list is on the explainer page.