Coal-Tar Driveway Sealant (PAHs)

Black sealer coating a drive, path or parking lot.

32High burden · out of 100

Cleaner swapAn asphalt-based sealer, or leaving the surface unsealed

How this score is built

100Start
63.2Chemical hazard 8 × 4.6−36.8
53Everyday exposure 3 × 3.4−10.2
32Persistence 8 × 2.6−20.8, then rounded to 32
HighThe band32 sits in 20–39.

What each input rests on

The three ratings behind the score, and the studies each rests on
Input	Rating	Evidence
Chemical hazard	8/10	unsourced input
Everyday exposure	3/10	In settled house dust from 23 apartments, total PAH was 25 times higher (median 129 against 5.1 µg/g) where the parking lot had coal-tar sealcoat than where it had other surfaces; sealcoat explained 48% of the variance. Coal-tar-based parking lot sealcoat: an unrecognized source of PAH to settled house dust · Environ Sci Technol 2010 DOI 10.1021/es902533r · PMID 20063893 · Abstract · read 2026-10-21
Persistence	8/10	unsourced input

Ratings are editorial. A study listed here supports the rating; it did not compute it. How the index is built

What this means for you

The chemical-hazard rating is what drives the score down. Coal-tar sealcoat is loaded with polycyclic aromatic hydrocarbons. Worn particles track indoors on shoes and tyres: US Geological Survey sampling found PAH in house dust about 25 times higher in homes beside coal-tar-sealed lots than beside plain asphalt or concrete.

Evidence strength: strong

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Lower-exposure choices

Regular Sauna UseMinimal · Environment

Regular Exercise & SweatMinimal · Environment

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