# Risk Assessment of Impairment of Fertility Due to Exposure to Tobacco Constituents Classified as Reprotoxicants

## TL;DR

This study assesses how harmful chemicals in tobacco can affect fertility and concludes that there is no safe level of tobacco exposure for people trying to conceive.

## Contribution

The study combines toxicological data and exposure estimates to evaluate fertility risks from tobacco constituents classified as reproductive toxicants.

## Key findings

- The combined risk ratio of exposure to five tobacco chemicals was 0.48.
- No safe dose could be derived for tobacco use in individuals seeking pregnancy.
- Both active and passive smokers face fertility risks from tobacco constituents.

## Abstract

Background: Epidemiological studies demonstrate that exposure to tobacco causes infertility. A reference cigarette contains up to 47 chemicals above the quantification level, of which acrylamide, benzopyrene, cadmium, ethylene oxide and lead are classified as known (category 1A), presumed (category 1B) or suspected (category 2) human reproductive toxicants due to their effects on fertility and sexual function. Methods: We collected toxicological information on these substances to establish their respective systemic-derived no-effect levels (internal doses predicted not to alter fertility). We also estimated the systemic exposure to these four substances by smokers consuming 20 cigarettes per day. Results: The risks (ratios between exposure and safe dose) were 0.23, 0.06, 0.18, 0.01 and 0.00002 for acrylamide, benzopyrene, cadmium, ethylene oxide and lead, respectively. The combined risk was 0.48. Conclusions: It was concluded that the changes in fertility resulting from the consumption of the substances in tobacco classified as toxic to fertility could not be explained by mechanisms with a toxicity threshold attributable to these five substances. No safe dose could be derived for tobacco use in persons seeking pregnancy; this applied to both active and passive smokers.