Health outcome · marker
Semen quality
Also: sperm quality, semen parameters, sperm parameters, semen analysis
The set of measurements made on a semen sample — concentration, total count, motility, morphology and volume — assessed against reference values. It is the standard way male fertility is described, and the level at which most environmental studies report.
What it is
Semen analysis is a panel, not a single number, and the parameters within it carry different information. Count reflects the three months of production behind the sample; motility responds to more recent conditions; morphology is the most operator-dependent of the three. A study that reports the panel as a whole is reporting something less precise than any of its parts.
The reference values are also widely misread. They are derived from the lower percentiles of men who recently fathered children, so a sample below them describes reduced probability rather than inability, and a sample above them is no guarantee.
For indoor air the attraction of this outcome is its sensitivity: it registers exposures long before infertility would, and it can be measured repeatedly in the same men. Its limitation is variability between samples from one individual, which is large enough that single-sample studies are weak evidence whatever their size.
Indoor factors with evidence
| Factor | Effect | Population | Study design | Source | Checked |
|---|---|---|---|---|---|
| Particulate matter (PM₂.₅ and PM₁₀) | SMD -0.028 (-0.055–-0.01) | men undergoing semen analysis | systematic review and meta-analysis of studies on ambient particulate matter and semen quality parameters (6264 participants in the included studies) | F-0228 Bahreiny Association between ambient particulate matter and semen qua… (2024) | machine |
Each row is one Finding — a sentence as printed in one study, recorded with its page in the Coridum Knowledge Base. Follow the Finding number for the exact wording and the citation. Checked says who verified the row: machine means every automatic check passed and the surrounding text was read; person means someone read the sentence in the document. Rows are re-checked by a person over time. The studies are curated in the Coridum Knowledge Base; the reading of them together is a Claim, shown separately.
Cite this page
Coridum Research. Semen quality. Coridum Knowledge G-0191, 16 September 2026. https://coridum.com/k/G-0191/