{"id":3498299,"date":"2023-09-12T08:49:40","date_gmt":"2023-09-12T08:49:40","guid":{"rendered":"https:\/\/www.resilience.org\/?p=3498299"},"modified":"2023-09-25T09:32:09","modified_gmt":"2023-09-25T09:32:09","slug":"why-2-is-the-most-dangerous-number-no-one-is-talking-about","status":"publish","type":"post","link":"https:\/\/www.resilience.org\/stories\/2023-09-12\/why-2-is-the-most-dangerous-number-no-one-is-talking-about\/","title":{"rendered":"Why 2% Is the Most Dangerous Number No One Is Talking About"},"content":{"rendered":"

We\u2019ve had a summer from hell, with July 2023 temporarily claiming the title of hottest month on record<\/a>. But while the klaxons of Earth\u2019s climate system have riveted nearly everyone\u2019s attention, something else is silently happening to us and other species that could turn out to be just as big a disaster.<\/p>\n

Nature is increasingly stewing in air- and water-borne toxins originating in industrial processes. Tens of thousands of chemicals<\/a>, only a tiny proportion of which have been tested for safety, are making their way into the environment\u2014from pharmaceuticals that have passed through human bodies, to plastics, pesticides, solvents, fire-retardants, and chemicals used in making cookware coatings.<\/p>\n

Recent research shows that whole classes of these chemicals are affecting sexuality and disrupting reproduction\u2014not just in humans, but in a host of other animal species as well. But the whole subject is controversial and is getting far too little attention, partly because reproduction and sexuality are culturally sensitive topics, and partly because the chemicals industry wields considerable political power. In this article, we\u2019ll explore both the science and the controversy, and see why 2 percent is such a scary number in this context.<\/p>\n

Sperm Counts, Testosterone Levels, and Women\u2019s Reproductive Health<\/strong><\/p>\n

Multiple studies<\/a> have shown that male sperm counts have fallen dramatically in the past 50 years. That decline appears to be accelerating.<\/p>\n

While the reasons for falling sperm counts are still being investigated, it is clear that the fetus is particularly susceptible to the effects of pollutants, and that impacts at the fetal stage of life can significantly shape the adult. The pollutants most likely to have widespread impacts on reproductive health have been identified\u2014hormone-mimicking chemicals that have become widely dispersed in the environment, many of which persist for decades or longer.<\/p>\n

Two meta-studies (i.e., studies based on a review of all relevant research to date) by a team led by Hagal Levine of the Hebrew University of Jerusalem provide the most reliable and broad-based scientific information about sperm counts. The first of these papers<\/a>, published in 2017, covered data from North America, Europe, and Australia\/New Zealand. It found \u201ca significant decline in sperm counts . . . between 1973 and 2011.\u201d<\/p>\n

A more recent paper<\/a> by Levine et al., published in November 2022, confirmed these conclusions and expanded them to include Africa and South America. Among men from all continents, the authors concluded, \u201cthe mean [sperm count] declined by 51.6% between 1973 and 2018.\u201d The study also found that the decline rate, currently about 2 percent per year, is increasing. The trend, if extrapolated, would result in near-universal male sterility by about 2060.<\/p>\n

Having a low sperm count reduces fertility, though if the count is above zero it does not exclude the possibility of an affected man impregnating his partner. However, a low sperm count is frequently associated with reduced sperm quality, including less motility and abnormal shape.<\/p>\n

Testosterone levels in males are also falling<\/a>. Several reasons<\/a> have been suggested, with environmental toxins again one of the more likely culprits. Low testosterone levels in men can lead to obesity, low sex drive, and symptoms of depression.<\/p>\n

Women are likewise experiencing puzzling and worrisome trends in sexuality and reproduction. Studies in dozens of countries since the 1970s have shown that girls are experiencing puberty<\/a> earlier and earlier, with the average age of onset declining by about three months with each passing decade (a similar, though less extreme pattern<\/a>, has been seen in boys).<\/p>\n

In her book Countdown: How Our Modern World Is Threatening Sperm Counts, Altering Male and Female Reproductive Development, and Imperiling the Future of the Human Race<\/em><\/a>, <\/em>reproductive epidemiologist Shanna Swan (a co-author with Levine of the two studies linked above) cites research showing an increase in difficulties in childbirth, increasing incidence of endometriosis, increasing risk of miscarriage, increasing incidence of ovulation disorders, and increasing use of in vitro fertilization.<\/p>\n

Swan also explores links between chemical exposure in utero and later gender-related sexual behavior, citing dozens of relevant studies. She writes:<\/p>\n

In addition to influencing the physiology of reproductive development, environmental chemicals may be affecting gender identity and sexual preference. These forms of flux aren\u2019t inherently good or bad, but they may present a silver lining: with such trends arguably on the rise, we, as a society, are gradually becoming more open-minded toward accepting people, however they present and identify themselves in terms of gender.<\/p><\/blockquote>\n

Meanwhile, Americans are having less sex<\/a>, and young people in particular are reporting less sex drive.<\/p>\n

Why Is This Happening? <\/strong><\/p>\n

There are several possible reasons for these ongoing shifts in human reproduction and sexuality. Researchers have explored environmental toxins, obesity, diet, smoking, medications, diabetes, marijuana usage, and aging as factors. It\u2019s difficult to establish perfect cause-and-effect relationships between culprits and outcomes, but all of the worrisome impacts and trends are linked, to one degree or another, with environmental toxins.<\/p>\n

Since the 1990s, many researchers who are trying to understand the accelerating increase in reproductive problems have focused on endocrine disrupting chemicals\u2014compounds that either block the action of a naturally occurring hormone or intensify the effects of a natural hormone by eliciting the same physiological response as the hormone itself. Endocrine disruptors include:<\/p>\n