- Despite ongoing concerns about overpopulation, birth rates are falling worldwide, and in many countries populations are projected to drop by half by the end of this century.
- Decreasing birth rates have been attributed to such social changes as increasing access to higher education for women, modern methods of contraception and economic considerations leading to fewer or no children by choice.
- A more ominous trend is represented by biologic indicators such as drastically decreased sperm counts in most developed nations, as well as increasing incidents of reproductive anomalies such as early puberty in girls and genital abnormalities in boys.
Warnings about a global population explosion and what that will mean to the future of the planet have been in the public consciousness for the past century, so it may be a bit confusing that recent reports show fertility rates are actually falling dramatically worldwide. Declining birth rates have been documented in developed countries since 1969 have often been attributed to better access to higher education for women,1 as well as increased access to modern methods of contraception.2
It has been predicted that populations will decline in almost every country by the end of the 21st century. It is further estimated that in 23 countries including Spain, Japan, Portugal, Thailand and South Korea, populations will fall by as much as half by 2100.3
Another 34 countries are expected to see declines of between 25 and 50 percent, including China, which is projected to see a decline of approximately 48 per cent.4 Only North Africa and the Middle East are expected to increase their populations by 2100 compared with 2017, with the population of sub-Saharan Africa expected to triple from approximately 1.03 billion in 2017 to close to 3.07 billion by 2100.5
U.S. Birth Rates Falling Since 2007
In the U.S., birth rates have been falling continually since 2007. The birth rate is currently lower in this country than it has ever been. Between 2019 and 2020, the rate declined by four percent, compared with a one to two percent drop between 2015 and 2019.6
According to Pamela Stamp of the University of Michigan, several factors are at play. Less stigma surrounding a choice not to have children is one factor. Another factor is changing gender roles, as more women seek higher education and careers. An unpredictable economy and climbing personal debt, including student debt, are other factors that may cause some women to delay childbearing or have fewer children than they might otherwise have had.
Stamp adds that uncertainty about jobs and the future during the COVID-19 pandemic also had an impact on decisions to have children, with birth rates in December of 2020—when babies conceived at the beginning of the pandemic would have been born—dropping by eight per cent compared to birth rates from December of 2019.7
Prediction: One Billion Person Drop in Global Population Between 2064 and 2100
A forecasting analysis published in The Lancet predicts that, “global population will peak in 2064 at 9.73 billion (95 percent UI 8·84–10·9) and then decline to 8.79 billion (6·83–11·8) in 2100.”8 While decreases in global population might provide significant planetary benefits, they are also expected to have profound “economic and fiscal consequences that will be extremely challenging.”
Changes in social structure, gender roles and increased access to education and life choices undoubtedly have affected birth rates, but these factors do not explain all of the changes being reported in reproduction and fertility worldwide.
According to Shanna Swan, environmental and reproductive epidemiologist at Icahn School of Medicine at Mount Sinai in New York and author of a new book on the subject (Count Down), “The current state of reproductive affairs can’t continue much longer without threatening human survival.” She warns that declining sperm counts and changes in sexual development are causing a fertility crisis that is “threatening human survival.”
Although Swan acknowledges that contraception, cultural shifts and economic considerations may contribute to falling fertility rates, she also points to biological indicators of a deeper problem. These include rising rates of miscarriage, increasing numbers of genital abnormalities among boys, and earlier puberty among girls.
Smoking Gun Chemicals in Toxic Environment
Primarily blaming falling fertility rates on chemicals, such as those found in plastics, cosmetics and pesticides that impact endocrine levels, Swan says, “Chemicals in our environment and unhealthy lifestyle practices in our modern world are disrupting our hormonal balance, causing various degrees of reproductive havoc.”9
Swan has been studying the environmental impact on fertility since the 1980s, when she was able to link a spike in miscarriages in Santa Clara, California, to drinking water contaminated by toxic waste from a local semiconductor plant. She has been studying sperm rates since 1997 and considers those numbers to represent the “canary in a coal mine.” In 2017, Swan’s meta-analysis of 40,000 men showed that sperm counts fell by 59 percent between 1973 and 2011.10
Swan’s emphasis on disruption of fertility by environmental chemicals is in keeping with findings of the World Health Organization (WHO), whose fact sheet on infertility reads, in part:
Environmental and lifestyle factors such as smoking, excessive alcohol intake and obesity can affect fertility. In addition, exposure to environmental pollutants and toxins can be directly toxic to gametes (eggs and sperm), resulting in their decreased numbers and poor quality, leading to infertility.11
The impact of environmental toxins on fertility has been recognized since at least 1860, when French scientists observed that women married to lead workers not only had a harder time conceiving but also a higher risk of miscarriage.12
Invisible Threat of Low Level Environmental Toxins
It has previously been established that people who work directly with pesticides have a higher risk of infertility,13 but several more recent studies indicate that even low, everyday levels of exposure to toxic chemicals found in water, soil, air and food has been reported to have a negative impact on the reproductive system.14 15
It is not only human fertility that is being affected. Mirroring humans’ increased prevalence of genital abnormalities, such as an increased incidence of males born with undescended testicles or atypically small penises, reproductive issues are also being reported in animal species. Examples include reduced fertility among Baltic gray seals, increasing numbers of polar bears with small genitals and low testosterone levels, and genital abnormalities reported in alligators, panthers and minks.16
Pesticide Residue on Fruits and Vegetables Compromises Fertility
One of the most common culprits identified is pesticide residue on fruits and vegetables, which has been linked to both lowered sperm counts and a decreased success rate of in vitro fertilization procedures.17 18 In a study of 325 women undergoing fertility treatments, researchers primarily from Harvard T.H. Chan School of Public Health in Boston, Massachusetts reported that “intake of high–pesticide residue fruits and vegetables was associated with a lower probability of live birth, while low–pesticide residue fruit and vegetable intake was not associated with this outcome.”19
In another study, Jorge Chavarro, MD and his associates at Harvard School of Public Health in Boston similarly observed that men who ate the most high-pesticide fruits and vegetables had both reduced sperm counts (49 per cent lower) and a higher number of misshapen sperm (32 per cent fewer healthy sperm) compared to men with the lowest dietary pesticide exposure.20 The researchers did not point to one pesticide in particular but suggested that a mixture of pesticides is responsible.
Following is their list of fruits and vegetables, ranked from highest (6) to lowest (4) risk, scored on the basis of level of detectable pesticide contamination, level in excess of U.S. Environmental Protection Agency guidelines and presence of three or more types of pesticides:
- Green, yellow and red peppers (6)
- Spinach (6)
- Strawberries (6)
- Celery (6)
- Blueberries (5)
- Potatoes (5)
- Peaches and plums (5)
- Apples or pears (5)
- Winter squash (4)
- Kale, mustard greens and chard greens (4)
- Grapes and raisins (4)
Other factors that may influence fertility for men and women include21:
- Age (> 35 in women and > 40 in men)
- Eating disorders
- Excessive alcohol use
- Exposure to environmental toxins
- Excessive exercise
- Cancer treatment, including radiology
- Sexually transmitted diseases (STDs)
- Smoking (both tobacco and marijuana have been implicated22
- Substance abuse
- Weight issues, whether under- or overweight
Most measurable scientific studies have concentrated on male fertility because male reproductive issues are simpler to evaluate. However, since other environmental toxins such as radiation, lead ethylene glycol ethers and cigarette smoke have been found to be as harmful for women as for men, it has been proposed that environmental factors damaging to the reproductive system would be expected to equally affect both men and women.23
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Click here to view References:
1 Le Grassa J. The Impact Of Education On Declining Birth Rates. The Silhouette Mar. 7, 2017.
2 Meredith S. Falling Fertility Rates To Trigger ‘Major Shifts’ In Economic Power, Research Predicts. CNBC World News July 15, 2020.
3 Gallagher J. Fertility Rate: ‘Jaw-Dropping’ Global Crash In Children Being Born. BBC News July 15, 2020.
4 Vollset SE, Goren E, Yuan C-W, et al. Fertility, Mortality, Migration, And Population Scenarios For 195 Countries And Territories From 2017 To 2100: A Forecasting Analysis For The Global Burden Of Disease Study The Lancet July 14, 2020.
5 Meredith S. Falling Fertility Rates To Trigger ‘Major Shifts’ In Economic Power, Research Predicts. CNBC World News July 15, 2020.
6 Smock P. What’s Behind The Falling U.S. Birthrate? Michigan News, Faculty Q and A May 13, 2021.
8 Vollset SE, Goren E, Yuan C-W, et al. Fertility, Mortality, Migration, And Population Scenarios For 195 Countries And Territories From 2017 To 2100: A Forecasting Analysis For The Global Burden Of Disease Study The Lancet July 14, 2020.
9 Bryant M. Falling Sperm Counts ‘Threaten Human Survival’, Expert Warns. The Guardian Feb. 26, 2021.
10 Cahalan S. Why More Men Are Suffering From Infertility Than Ever Before. New York Post Feb. 20, 2021.
11 Infertility. World Health Organization. Sept. 14, 2020.
12 The Impact of The Environment on Your Fertility. Fertility Factor 2021.
13 Elton C. Pollutants Linked to Lower Fertility in Both Men and Women. Time Nov. 15, 2012.
14 Oaklander M. A Diet High in Pesticides Is Linked to a Lower Sperm Count. Time Mar. 30, 2015.
15 The Impact of The Environment on Your Fertility. Fertility Factor 2021..
16 Cahalan S. Why More Men Are Suffering From Infertility Than Ever Before. New York Post Feb. 20, 2021.
17 Park A. Pesticides In Produce Linked to Women Not Getting Pregnant with IVF. Time Oct. 30, 2017.
18 Chiu Y-H, Williams PL, Gillman MW, et al. Association Between Pesticide Residue Intake From Consumption of Fruits and Vegetables and Pregnancy Outcomes Among Women Undergoing Infertility Treatment With Assisted Reproductive Technology. JAMA January 2018.
20 Oaklander M. A Diet High in Pesticides Is Linked to a Lower Sperm Count. Time Mar. 30, 2015.
21 Infertility Causes. Cleveland Clinic Dec. 14, 2020.
22 Bryant M. Falling Sperm Counts ‘Threaten Human Survival’, Expert Warns. The Guardian Feb. 26, 2021.
23 The Impact of The Environment on Your Fertility. Fertility Factor 2021.