Free Water & Air Audit
for Your ZIP Code.
Enter your ZIP code to see local PFAS, lead, and PM2.5 levels. WaterAirAudit translates the numbers into health impacts and recommends filters that actually remove what's in your supply.
Interactive Water & Air Quality Risk Map
Every U.S. state colored by its regional composite for PFAS, lead, and PM2.5. Switch the filter to see which pollutant drives each region's risk. Click a state to audit its representative ZIP.
PFAS, Lead & PM2.5 — The Three Pollutants We Track
There are dozens of regulated contaminants. PFAS, lead, and PM2.5 combine ubiquity, severity, and accessible mitigation — meaning if you only fix one thing, fix one of these.
PFAS
Drinking WaterPer- and polyfluoroalkyl substances — "forever chemicals" used in nonstick coatings, firefighting foam, and stain repellents. They don't break down in nature or in your body.
Lead
Drinking WaterLeaches into water from lead service lines and older fixtures. There is no safe level of lead exposure, especially for children. Effects are cumulative and largely irreversible.
PM2.5
Indoor + Outdoor AirFine particles smaller than 2.5 microns. They cross from lung into bloodstream, driving cardiovascular and neurological damage. Indoor levels often track outdoor.
Health Impacts at a Glance
What the epidemiological literature actually says. Linked sources are peer-reviewed or from public health agencies.
PFAS — What They Do
- Cancer: EPA classifies PFOA as "likely carcinogenic" and PFOS as having "suggestive evidence." Kidney and testicular cancers most strongly linked.
- Immune suppression: Reduces vaccine antibody response in children — well-documented across multiple cohorts.
- Liver effects: Elevated liver enzymes; associations with non-alcoholic fatty liver disease.
- Cholesterol: Higher LDL and total cholesterol with increasing serum PFAS.
- Developmental: Lower birth weight, accelerated puberty, thyroid disruption.
PFAS bioaccumulate. Half-life in human serum is years to decades — exposure today is exposure for life.
Lead — What It Does
- Children: Even very low blood-lead levels are associated with measurable IQ deficits, attention problems, and behavioral changes.
- Cardiovascular: Lead exposure is now estimated to cause more deaths from cardiovascular disease than from acute poisoning.
- Kidney: Chronic exposure damages renal function over decades.
- Pregnancy: Crosses placenta; associated with preterm birth and reduced fetal growth.
- Neurological (adult): Cognitive decline associated with long-term cumulative exposure.
Lead damage is largely permanent. Prevention is the only effective intervention.
PM2.5 — What It Does
- Cardiovascular: Strongest evidence — long-term PM2.5 exposure raises mortality from heart attacks, strokes, and arrhythmias.
- Respiratory: Worsens asthma, COPD, and increases risk of lung cancer (IARC Group 1 carcinogen).
- Neurological: Growing evidence linking chronic PM2.5 to dementia and accelerated cognitive aging.
- Metabolic: Associated with type 2 diabetes incidence and metabolic syndrome.
- Mortality: Each ~10 µg/m³ increase in long-term exposure tied to ~6–8% increase in all-cause mortality.
No safe threshold has been established. WHO's guideline (5 µg/m³) is well below the U.S. standard.
Highest-Risk Groups
Children, pregnant people, older adults, and anyone with cardiovascular or respiratory disease should weight these exposures most heavily. If you fall into one of these groups, the case for filtration and indoor air management is strong even at "moderate" levels.
Water Filter & Air Purifier Guide — What Actually Removes What
Marketing claims are loose. These are the filtration mechanisms backed by NSF/ANSI standards for PFAS, lead, and PM2.5. Match the certification to your contaminant.
If lead is your concern
Any NSF 53-certified carbon block at the kitchen tap will do the job. Look for "lead reduction" specifically — not all carbon filters are certified for it. Replace cartridges on schedule.
If PFAS is your concern
Reverse osmosis at the point of use (under-sink) is the gold standard, removing 95%+ of PFAS. Berkey-style gravity systems with PF-2 cartridges are a secondary option. Standard pitcher carbon is not enough.
If PM2.5 is your concern
True HEPA air purifier sized for the room (target 4–5 air changes/hour). For wildfire smoke or persistent outdoor PM2.5, run continuously and seal the room. MERV 13+ HVAC filters help system-wide.
If you want one solution
For homes with multiple concerns, a whole-house carbon system + under-sink RO + bedroom HEPA covers the realistic threat surface. Total cost: roughly $700–$1,400 for capable mid-tier gear.
Research & Evidence Base
Peer-reviewed and agency sources behind the recommendations. Every claim above traces to one of these.
EPA Final PFAS Drinking Water Standards
In April 2024 the EPA issued the first-ever enforceable drinking water standards for six PFAS compounds, including PFOA and PFOS at 4 parts per trillion. Utilities have until 2029 to comply.
EPA: PFAS Drinking Water →Grandjean et al. — Vaccine Antibody Response
Landmark Faroe Islands cohort showing children with higher PFAS exposure had reduced antibody response to routine childhood vaccinations, demonstrating immunotoxicity at common environmental levels.
PubMed →Lanphear et al. — Low-Level Lead and IQ
Pooled analysis of seven prospective cohorts found a steeper dose-response relationship at the lowest blood-lead levels, confirming there is no observable threshold below which lead is safe for children.
PubMed →Lanphear et al. — Lead and Cardiovascular Mortality
Analysis of NHANES data estimated low-level lead exposure may contribute to ~412,000 U.S. deaths annually, primarily from cardiovascular disease — far higher than previously recognized.
The Lancet Public Health →Pope & Dockery — Long-Term PM2.5 and Mortality
Foundational analyses (Six Cities, ACS) established that each ~10 µg/m³ long-term increase in PM2.5 raises all-cause mortality by 6–13%, with cardiovascular and lung cancer effects most prominent.
PubMed →WHO Global Air Quality Guidelines (2021)
WHO sharply tightened PM2.5 guideline from 10 to 5 µg/m³ annual after re-analysis showed substantial mortality risk well below older thresholds. Most U.S. cities exceed this guideline.
WHO Guidelines →Andrews & Naidenko — Filter Performance for PFAS
EWG laboratory testing comparing point-of-use filters found reverse osmosis and two-stage carbon achieved >95% PFAS reduction; many pitcher filters performed inconsistently.
EWG Filter Study →Lead and Copper Rule Revisions
EPA's revised Lead and Copper Rule mandates full lead service line replacement within 10 years for most U.S. utilities and lowers the action level from 15 to 10 ppb starting 2027.
EPA: LCRI →Look Up Your Own Data
EWG Tap Water Database
Searchable database of utility test results across the U.S.
EPA AirNow
Real-time and historical PM2.5 + AQI by location
Consumer Confidence Reports
Annual water quality report your utility is required to publish
CDC Childhood Lead Program
Testing programs and prevention guidance
Frequently Asked Questions
Science-backed answers to the most common questions about tap water safety, PFAS, lead, PM2.5, and filtration.
Is tap water safe to drink in the United States?
For most people, municipal tap water meets federal legal standards — but "legal" and "safe" are not the same. The EPA's 2024 PFAS limit of 4 parts per trillion reflects decades of evidence, yet an estimated 45% of U.S. tap supplies have detectable PFAS at some level. Roughly 9.2 million homes still connect via lead service lines. Enter your ZIP code above to see what's documented in your area, and check your utility's annual Consumer Confidence Report.
What are PFAS, and are they in my drinking water?
PFAS (per- and polyfluoroalkyl substances) are a family of thousands of synthetic chemicals used in nonstick cookware coatings, firefighting foam, water-resistant textiles, and food packaging. They are called "forever chemicals" because they do not break down in the environment or in the human body, accumulating in serum with half-lives of years to decades. The EPA set its first enforceable drinking water limits in April 2024: 4 ppt for PFOA and PFOS. Studies estimate over 200 million Americans are exposed at some level.
What water filter removes PFAS?
Reverse osmosis (RO) is the most effective point-of-use technology, removing 95%+ of PFAS and certified to NSF/ANSI 58. Two-stage activated carbon block filters certified to NSF P473 can also significantly reduce PFAS, though performance varies by brand. Standard pitcher carbon filters (basic Brita, PUR, etc.) are not certified for PFAS removal and should not be relied upon. For whole-house coverage, a dedicated activated-carbon system rated for PFAS is needed. See the full filtration guide →
Does a Brita or standard pitcher filter remove PFAS or lead?
Standard pitcher filters (basic Brita, PUR, etc.) reduce chlorine and improve taste, but most are not certified to remove PFAS. Some premium pitchers (Clearly Filtered, ZeroWater) are independently tested for PFAS reduction. For lead, look specifically for NSF/ANSI 53 certification labeled "lead reduction" — not all carbon cartridges carry this. An upgrade to an under-sink reverse osmosis system remains the most reliable solution for both PFAS and lead in a single unit.
How do I know if I have lead pipes?
The age of your home is the strongest signal: homes built before 1986 are at highest risk since lead solder and lead service lines were common until the EPA banned them that year. Homes built before 1930 may have all-lead service lines. Under the EPA's Lead and Copper Rule Revision (LCRI), utilities must now provide a service line inventory — contact your utility or check their LCRI disclosure. An at-home water test (like Tap Score) is the only way to confirm actual lead levels at your tap.
What is the EPA's PFAS limit for drinking water?
In April 2024 the EPA finalized the first national drinking water standards for PFAS: 4 parts per trillion (ppt) for PFOA and PFOS individually, and a combined Hazard Index limit for PFNA, PFHxS, HFPO-DA (GenX), and PFBS. Water utilities must achieve compliance by 2029. This is the strictest PFAS drinking water standard in the world. Previously there was no federal enforceable limit.
What are the health effects of PFAS exposure?
PFAS accumulate in human tissue with serum half-lives of years to decades. Documented effects include:
- Immune suppression — reduced vaccine antibody response in children (Grandjean et al., 2012)
- Cancer — EPA classifies PFOA as "likely carcinogenic"; kidney and testicular cancers most strongly linked
- Cholesterol — higher LDL and total cholesterol with increasing serum PFAS
- Developmental — lower birth weight, accelerated puberty, thyroid disruption
- Liver — elevated enzymes; associations with non-alcoholic fatty liver disease
Because exposure accumulates over a lifetime, reducing ongoing intake is the most effective intervention even after past exposure has occurred.
Does a HEPA air purifier actually reduce PM2.5?
Yes — true HEPA filters capture ≥99.97% of particles ≥0.3 µm, which covers the entire PM2.5 size range. For effective reduction: the filter must be certified "true HEPA" (not "HEPA-type" or "HEPA-like"), the unit must be sized for your room (target 4–5 air changes per hour), and it must run continuously. AHAM Verifide CADR ratings are the most reliable independent measure of real-world performance. During wildfire events, keep windows closed and run the purifier on high.
How do I test my tap water for PFAS and lead?
The most thorough option is a certified laboratory kit: Tap Score's Advanced City Water Test covers 110+ contaminants including PFAS, lead, and disinfection byproducts, and returns a detailed health-context report. Your utility is also required to publish an annual Consumer Confidence Report (CCR) listing tested contaminant levels — though it reflects the treatment plant output, not necessarily your specific tap. A lab test remains the gold standard for confirming what you're actually drinking. See testing kits →
Is indoor air quality worse than outdoor air quality?
Often yes. The EPA estimates Americans spend about 90% of their time indoors, and indoor air can contain 2–5× higher concentrations of some pollutants than outdoor air. Buildings concentrate cooking byproducts, VOCs from furniture and cleaning products, and outdoor PM2.5 that infiltrates through gaps. A continuous air quality monitor (like the Airthings View Plus) will show your actual indoor PM2.5 levels in real time so you can verify whether your purifier is doing its job.
Recommended Water Filters & Air Purifiers
Products selected for independent third-party certification (NSF/ANSI, AHAM, CARB) and real-world performance.
Affiliate disclosure: links below may earn a commission at no extra cost to you.
💧 Water Filtration — Best for PFAS & Lead
AquaTru Countertop Reverse Osmosis
Tested to NSF 58, 53, 42, and 401. Independently shown to remove >95% of PFAS, lead, chromium-6, and arsenic. No plumbing required — sits on your counter. Best PFAS-removal value.
Berkey Big Berkey + PF-2 Fluoride/Lead Filters
Gravity-fed system using Black Berkey elements + PF-2 add-ons for lead and fluoride. No electricity, no plumbing. Tested to NSF P231 for microorganisms; PFAS removal moderate.
Clearly Filtered Pitcher
Independent lab testing claims removal of 365+ contaminants including PFAS and lead. More effective than typical pitcher carbon, though slower flow rate. Good entry-level option.
Aquasana Whole House + Salt-Free Conditioner
Whole-house carbon for PFAS reduction at every tap, plus a salt-free conditioner. Best for homes with documented contamination and the budget for a one-time installation.
🌫 Air Purification — Best for PM2.5
Blueair Blue Pure 211i Max
HEPASilent technology rated for rooms up to 635 sq ft. Quiet, energy-efficient, AHAM Verifide. Strong CADR for PM2.5 at lower price than Molekule. Excellent value.
Coway Airmega 400S
True HEPA + activated carbon, 1,560 sq ft coverage with smart sensors. Consistently ranks at the top of independent reviews. Lower running cost than premium brands.
IQAir HealthPro Plus
HyperHEPA filter rated to 0.003 microns — well below standard HEPA. Hospital-grade build quality. The choice when air quality is non-negotiable (wildfire zones, severe asthma).
🧪 At-Home Testing — Verify Before You Filter
Tap Score Advanced City Water Test
Lab-analyzed kit covering 110+ contaminants including PFAS, lead, and disinfection byproducts. Detailed report with health context. Used by environmental journalists and researchers.
Airthings View Plus PM2.5 Monitor
Continuous monitor for PM2.5, CO², radon, VOCs, humidity, and temperature. Phone app + historical trends. Closes the loop after installing a purifier — actually verify the result.