Our Everyday Environment & Fertility
As I sit here and type this on my laptop, I look across at my husband and see he is also working on his computer. As a reproductive endocrinology and infertility subspecialist I pause, wondering if we are causing damage to our eggs and sperm by having the laptop perched on our pelvis for hours each evening.
I realize he carries his cell phone in his pocket daily as well. Radiofrequency electromagnetic fields and continued heat exposure from these devices are just one example of how our everyday life exposures can impair our fertility. Several articles have suggested an association between laptop and cell phone use and impaired sperm motility and quality in men.
I realize as I begin to replay my day that I had countless concerning environmental exposures. My lunch had more trans fats than I would like to admit and I'm sure that I am still under the recommended 10,000 steps or 30 minutes of recommended cardio exercise per day. Those are in my control and I should do better. I take comfort in the fact that I am a non-smoker and my morning coffee and evening glass of red wine may have had some antioxidant benefits. My multivitamin does offer several fertility and pregnancy advantages and now there are studies suggesting men desiring pregnancy may also benefit from a multivitamin.
However, increasing evidence suggests that we should also be concerned about many things that are less in our control. No matter if you live in the city, on a farm, in a suburb, or bike to work, you are exposed to environmental toxins every day. They are in the air, soil, water, and food and both inside and outside the home. Many of these are related to the processes of industrialization, advancing technology and food preservation and, in reality, impossible to avoid. My shampoo, conditioner, hairspray, facial lotion, make-up nail polish and daily perfume were all culprits today. That lunch protein bar and bottled water… sure it had less bad fats but the preservatives and plastic wrappings are not ideal. My bottled water had been sitting in its plastic container for months, I am sure of it. And, now that I think about it, I never did look at the bottom for that number people tell me I should avoid.
These are all items contributing to our often continuous, daily exposure to phthalates. Phthalates is a group of commonly used chemicals to make plastics more malleable, products more lubricated or perfumed products oily. That new car smell that everyone loves-—yes, you guessed it—-phthalates in the plastic dashboard and other parts of the car create that smell. In reality, scientists have likely only studied 5% or less of environmental chemicals when it comes to reproductive health, so much is unknown.
Endocrine Disrupting Chemical (EDC):
EDCs are chemicals that disrupt, alter, or adversely affect how hormones work in our bodies, and phthalates are just one example. They are incredibly difficult to study due to variations and combinations of exposures over one’s lifetime. Numerous publications have linked exposure to EDCs to increased incidence of cancers, cardiovascular disease, metabolic disease, obesity, earlier puberty, pregnancy complications, and, more recently, infertility. Specifically, increasing EDC exposure has been associated with reduced sperm quality, increased miscarriage and time to pregnancy, polycystic ovarian syndrome (PCOS), endometriosis, and earlier age at menopause.
Germaine Buck Louis and colleagues at the NIH followed 500 couples as they just started to attempt pregnancy as part of the LIFE study in order to determine if increasing exposure to EDCs were associated with reduced fertility. Just after this we published an in depth analysis demonstrating that exposure to 15 EDCs (nine PCBs, three pesticides, a furan, and two phthalates) was associated with an earlier age at natural menopause, potentially two-fold more impactful than smoking cigarettes. This was a large population based study of US women supported by the NIH/CDC.
Four particular polychlorinated bisphenyls (PCBs) were implicated in both of these studies (PCB 118, 138, 156, 170).
While these were banned in the 1970’s and 1980’s, PCBs still exist today due to their incredibly long half-life and ubiquitous nature in the environment. These we just can’t get away from. They were once used as insulating material in electrical equipment like transformers, as lubricants, paints, adhesives, flame retardants, plasticizers and many more. They may be in landfills, evaporating from our waters or passed for decades in the food, soil and animals.
PCBs, phthalates, pesticides, flame-retardants, dioxins, phenols, polyaromatic hydrocarbons, and phytoestrogens-these are all examples of EDCs that can potentially cause adverse health outcomes. Some of us may be more genetically predisposed. It may be a synergistic effect of combinations of environmental exposures that cause more a profound impact. These are the things scientists and clinicians wonder on a regular basis.
At What Age Does Exposure Have the Greatest Impact on Fertility?
It is tough to determine the most crucial window. However, it's important to understand that the potential window for environmental exposure continues from embryonic life until death. In utero exposure to environmental toxins may impact hormonal actions, genital development, and development of ovaries or testicles of the developing offspring based on both animal and human studies.
Females have the maximum number of eggs they will ever have in life when they are 20- week-old fetuses. Approximately 90% of oocytes, or eggs, are lost by the time a young girl starts puberty. While that seems frightening, as long as a normal pool is established in utero and nothing accelerates the loss, there should still be enough for pregnancy to occur during the reproductive years.
There may be more of a potential for men to improve sperm quickly by minimizing environmental exposures since it takes approximately 75-85 days for a sperm to progress from production to ejaculation, gaining progressive motility and maturation along the way. On the other hand, data suggests the egg a woman ovulates this month took a minimum of 6-8 months to develop from a primary, or very tiny, egg/follicle. Some researchers feel lifestyle and supplemental changes for a woman may need to be on board for many months to see an impact in egg quality, if the potential for such exists.
Can We Minimize Our Exposure?
For many PCBs and other byproducts of industrialization, the answer is no. Over 80,000 synthetic chemicals are registered in the US and thousands of new ones added each year. Many things can’t be avoided and are even in the air we breathe and the soil. However, we may be able to minimize our exposure to other EDCs or make healthier choices.
Phthalates are one good example. In the late 1990’s there was increasing suggestion that everyday exposure to BPA was a health concern. In the 2000’s numerous publications suggested further association. In 2012 the FDA banned the use of BPA iIn baby bottles. It was during this time the “BPA-free” fad propagated to many consumer and infant products.
But pick up any product in a store and try to make heads or tails of the ingredient list. Shampoos and conditioners are just another example. Even if BPA is removed, something else is in its place to make that pacifier nipple soft, that medical IV tubing malleable, or that lotion, nail polish, shampoo have the gelled texture that it does or add the fragrance many desire.
Diethylphthalate (DEP) is still a phthalate commonly used in personal care products. Buying organic products may help decrease exposure but it's never a guarantee. Often times on labels words like “fragrance” may imply phthalates and related products. Furthermore, many times all specific ingredients do not need to be on a label because it is considered proprietary information.
Tips for Navigating the Real World:
While research is still scarce on most chemicals, here are a few things to consider that could potentially be beneficial for your reproductive health based on what is currently published:
(1) Avoiding smoking, increasing exercise and maintaining a healthy well-balanced diet is good for many aspects of your health, including fertility
(2) Women and men may benefit from a multivitamin
(3) Always strive for a healthy weight as obesity impacts fertility, pregnancy and potentially how we process and store EDCs
(4) For men, medications such as pain meds, and especially testosterone, will negatively impact sperm quality and quantity
(5) Don’t assume the more supplements the better; remember these aren’t as well regulated and not all ingredients are listed. Interactions with other medications occur so inform your physician about all over the counter supplements and products
(6) Consideration of organic products may minimize exposures to harmful environmental chemicals
(7) Always wash all produce (even those with peels) to remove pesticides and chemicals
(8) Eat less foods with preservatives and avoid artificial sweeteners
(9) Do not microwave on plastics as phthalates may leach into foods and liquids
(10) Use glass or stainless steel containers, especially for drinking water
(11) If using plastic bottles for food or personal care containers check the bottom of the bottle for the number that tells you about the type of plastic. Many publications and manufacturers suggest avoiding the numbers 3 (polyvinyl chloride or PVC; often used in bags flooring and contains phthalates and other chemicals) and 7 (this is the catch all “other” category that is less predictable and often contains BPA and/or other phthalates). Some would suggest also avoiding #6 which is polystyrene, otherwise known as Styrofoam and can leach styrene into food.
(12) Consider drinking filtered tap water if your tap water is safe
(13) Use more “green” household cleaning and lawn products as they may be less toxic
(14) BPA or phthalate-free labels are an improvement but not a safety guarantee
(15) Consider fragrance free products as this is often a source of EDCs and proprietary information
(16) Ask your salons about their hair, skin and nail products
(17) Fish is good for you (and baby when pregnant) just educate yourself regarding the fish and try to minimize mercury, PCBs and dioxins
(18) Consider unbleached or non-chlorine bleached paper, tampons and filters for coffee
(19) Supporting large scale policy improvements and environmental research is important
There is so much still to learn. Awareness and education are key, along with continued research. Many of these suggestions are likely beneficial for your overall health and not just fertility. For now, we did move our laptops up to the table. Our kids eat on the same dishes we do and we got rid of all the plastic kids plates and “sippy cups” as soon as we could. Our life is harried at times with our schedules but we eat fresh produce when we can and teach the kids about food and the environment. We have to continue to advance our knowledge in both genetics and the environment in order to continue down the path of personalized medicine. Now if only I could understand the ingredients on the back of my shampoo bottle…