Contraceptive Options and Their Associated Estrogenic Environmental Loads: Relationships and Trade-Offs

This work explores the relationships between a user's choice of a given contraceptive option and the load of steroidal estrogens that can be associated with that choice. Family planning data for the USA served as a basis for the analysis. The results showed that collectively the use of contraception in the USA conservatively averts the release of approximately 4.8 tonnes of estradiol equivalents to the environment. 35% of the estrogenic load released over the course of all experienced pregnancies events and 34% the estrogenic load represented by all resultant legacies are a result of contraception failure and the non-use of contraception. A scenario analysis conducted to explore the impacts of discontinuing the use of ethinylestradiol-based oral contraceptives revealed that this would not only result in a 1.7-fold increase in the estrogenic loading of the users, but the users would also be expected to experience undesired family planning outcomes at a rate that is 3.3 times higher. Additional scenario analyses in which ethinylestradiol-based oral contraceptive users were modeled as having switched entirely to the use of male condoms, diaphragms or copper IUDs suggested that whether a higher or lower estrogenic load can be associated with the switching population depends on the typical failure rates of the options adopted following discontinuation. And, finally, it was estimated that, in the USA, at most 13% of the annual estrogenic load can be averted by fully meeting the contraceptive needs of the population. Therefore, while the issue of estrogen impacts on the environment cannot be addressed solely by meeting the population's contraceptive needs, a significant fraction of the estrogenic mass released to environment can be averted by improving the level with which their contraceptive needs are met.本研究探讨了使用者对特定避孕方式的选择，与其相关的甾体雌激素（steroidal estrogens）负荷之间的关联，分析以美国计划生育数据为基础开展。研究结果显示，美国整体的避孕措施保守估计可避免约4.8吨雌二醇当量（estradiol equivalents）向环境中释放。在所有已发生妊娠事件期间释放的雌激素负荷中，35%源于避孕失败与未采取避孕措施；而所有妊娠结局所遗留的雌激素负荷中，34%同样源自此类情形。本研究开展一项情景分析，以探讨停用基于炔雌醇（ethinylestradiol）的口服避孕药所带来的影响。结果显示，此举不仅会使使用者的雌激素负荷升高1.7倍，还会导致使用者出现不良计划生育结局的概率提升至原水平的3.3倍。后续开展的额外情景分析中，研究人员将停用炔雌醇口服避孕药的人群模拟为完全改用男用避孕套、阴道隔膜或含铜宫内节育器（copper IUDs）的群体。分析结果表明，该转换人群的雌激素负荷升高还是降低，取决于停用避孕药后所选用的避孕方式的典型失败率。最后，研究估算得出：在美国，若完全满足全体人群的避孕需求，最多可避免13%的年度雌激素负荷排放。因此，尽管仅通过满足人群的避孕需求无法完全解决雌激素对环境的影响问题，但通过提升避孕需求的满足率，仍可避免相当一部分向环境中释放的雌激素总量。