The pain during menstruation are calleddysmenorrhea: this dysmenorrhea is said to be “primary” when it appears from the first menstruation in adolescents and “secondary” when it occurs in young women at a distance from puberty.
What are the causes of dysmenorrhea?
In this last case, a sickness involved is sought as endometriosis, uterine fibroid or polyps. The causes of dysmenorrhea can also be a copper intrauterine device especially if it is moved or a change in hormonal contraception. In the review Frontiers in Public Health, researchers from China Medical University Hospital in Taiwan claim to have identified another factor, directly linked to the environment: Pollution.
They claim that long-term exposure to atmospheric pollutants such as nitrogen dioxide and carbon monoxide and fine particles greatly increases the risk of developing dysmenorrhea. Based on long-term air quality and public health data collected from national databases, their study shows that the risk of developing dysmenorrhea over a 13-year period was up to 33 times higher in women and girls who lived in areas with the highest levels of air pollutants compared to their peers exposed to lower levels of pollutants.
Pollution increases the secretion of prostaglandins
The symptoms of dysmenorrhea include cramps and pain in the lower abdomen, pain in the lower back and legs, nausea and vomiting, diarrhea, fatigue, feeling sick and headache. In addition to reducing the quality of life, dysmenorrhea also has a major socio-economic impact, since women who have it may be temporarily unable to work, go to school or indulge in hobbies. If no cure is known, symptoms can be treated with nonsteroidal anti-inflammatory drugs (which decrease blood pressure). secretion of prostaglandins, causing pain) and hormonal contraceptives.
“Research has already shown that women who smoke or drink alcohol during their period, who are overweight or who have their first period very young, run more high risk of dysmenorrhea. Those who have never been pregnant also. But here we demonstrate for the first time another important risk factor for dysmenorrhea: air quality, especially long-term exposure to pollution », Explains Professor Chung Y. Hsu, one of the authors of the study. The hypothesis would be that pollutants promote the production of a higher level of prostaglandins: these substances are synthesized in the tissues and act on muscle tone, in particular uterine contractility.
Fine particles, the most dangerous pollutant
Researchers studied health data from 296,078 women aged between 16 and 55 over a period ranging from 200 to 2013, all with no recorded history of dysmenorrhea. They looked for a long-term association between the risk of dysmenorrhea et air quality, in particular exposure over several years to different types of air pollutants: nitrogen oxide, nitric oxide, nitrogen dioxide, carbon monoxide and particles less than 2.5m in diameter (PM2.5). The results showed that during the study period (2000 to 2013), 4.2% of the women in the study sample were diagnosed with dysmenorrhea for the first time.
These are especially younger women, low-income women and especially those living in more urbanized areas who had the highest risk of developing dysmenorrhea during the study period. Thus, the “risk ratio”, or the risk specific to age and year, of developing dysmenorrhea was multiplied by 33.1 for women who lived in areas with the highest annual exposure to them. pollutants, compared to those living in less exposed areas. While each pollutant separately contributed to the increased risk, the largest individual effect came from a long term exposurewith fine particles (PM2.5).
Since 2013, the outside air particles are classified as carcinogenic to humans by the International Agency for Research on Cancer. The toxicity of these particles coming from both their composition and their size, knowing that the finer they are, the more they are capable of penetrate deep into the body and pass through the bloodstream to other organs. “Our results show that the overall impact of air quality on health, but specifically on the risk of dysmenorrhea. It is a clear illustration of the need for actions by government agencies and citizens to reduce air pollution », Concludes Professor Pr Chung Y. Hsu.