People who work outside in the sun every day, especially sailors and gardeners, have a much higher chance of getting skin cancer than people who work indoors—even more than other outdoor jobs like paving roads.
Scientific Claim
Among outdoor workers in Lisbon, occupations with the highest estimated annual UVR exposure—such as sailors, gardeners, gravediggers, and sanitation workers—show the greatest relative risk of squamous cell carcinoma, with sailors exhibiting up to a 2,093% increased risk after 40 years of exposure.
Original Statement
“The one Sailor had the highest annual occupational exposure to solar UVR (1,087 SED)... Relative risk for SCC due to 40-year outdoor work: Sailor: 21.9 (2,093% increased risk)... Gardeners, Gravediggers, and Sanitation Workers followed, with similar annual exposures, ranging from 361 to 382 SEDs.”
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design supports claim
Appropriate Language Strength
association
Can only show association/correlation
Assessment Explanation
The study reports observed associations between measured UVR doses and modeled SCC risk by occupation. The language reflects correlation, not causation, and is appropriate for an observational design.
Gold Standard Evidence Needed
According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.
Systematic Review & Meta-AnalysisLevel 1aIn EvidenceThe relative risk ranking of SCC across occupational categories (e.g., sailor vs. gardener vs. paver) in diverse global populations with standardized UVR exposure metrics.
The relative risk ranking of SCC across occupational categories (e.g., sailor vs. gardener vs. paver) in diverse global populations with standardized UVR exposure metrics.
What This Would Prove
The relative risk ranking of SCC across occupational categories (e.g., sailor vs. gardener vs. paver) in diverse global populations with standardized UVR exposure metrics.
Ideal Study Design
A meta-analysis of 15+ cohort or case-control studies from Europe, North America, and Australia, using consistent UVR exposure classification (e.g., dosimetry or job-exposure matrices) and adjusting for latitude, skin type, and sun protection, to rank SCC risk by occupation.
Limitation: Cannot account for within-occupation variability in tasks or protective behaviors.
Prospective Cohort StudyLevel 2aThe prospective incidence of SCC by specific occupation over time, with UVR exposure measured daily via dosimetry.
The prospective incidence of SCC by specific occupation over time, with UVR exposure measured daily via dosimetry.
What This Would Prove
The prospective incidence of SCC by specific occupation over time, with UVR exposure measured daily via dosimetry.
Ideal Study Design
A 15-year prospective cohort of 2,000+ workers in Lisbon across six occupations (sailor, gardener, gravedigger, sanitation, paver, asphalt), wearing UVR dosimeters daily, with annual dermatological exams and biopsy-confirmed SCC diagnosis.
Limitation: High cost and attrition may limit statistical power for rare outcomes like SCC.
Population-Based Case-Control StudyLevel 2bThe odds ratio of SCC for each occupation compared to indoor workers, with exposure quantified by validated job history and dosimetry.
The odds ratio of SCC for each occupation compared to indoor workers, with exposure quantified by validated job history and dosimetry.
What This Would Prove
The odds ratio of SCC for each occupation compared to indoor workers, with exposure quantified by validated job history and dosimetry.
Ideal Study Design
A case-control study of 800 SCC cases and 1,600 controls in Portugal, matched for age, skin type, and region, with UVR exposure assessed via 7-day personal dosimetry and detailed occupational history, stratified by job title.
Limitation: Recall bias in job history and difficulty capturing intermittent exposure patterns.
Evidence from Studies
Supporting (0)
Contradicting (1)
The study found that outdoor workers like gardeners and sanitation workers have a higher risk of skin cancer from sun exposure, but it didn’t find that sailors have over 20 times the risk as the claim says — so the claim is too extreme and not backed by this research.