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U.S. government agencies (such as FDA) say phthalates are OK, but evidence is mounting that they definitely are not OK. It's impossible to totally avoid phthalates, but one can lower exposure amounts by eating whole unprocessed foods, not microwaving or storing food in plastic containers (best is glass), and read ingredient lists on labels, including personal care products. From Medical Xpress:

Plastics chemical tied to changes in boys' reproductive development

When expectant mothers are exposed to plastics chemicals called phthalates during the first trimester, their male offspring may have a greater risk of infertility later in life, a new study suggests.Boys exposed to the chemical diethylhexyl phthalate (DEHP) may be born with a significantly shorter anogenital distance than those not exposed to these chemicals. Anogenital distance is the distance between the anus and the genitals. A shorter anogenital distance has been linked to infertility and low sperm count, the researchers explained.

"We saw these changes even though moms' exposure to DEHP has dropped 50 percent in the past 10 years," said lead researcher Shanna Swan, a professor of preventive medicine and obstetrics, gynecology and reproductive medicine at the Icahn School of Medicine at Mount Sinai in New York City. "Therefore, we have not found a safe level of phthalate exposure for pregnant women," she contended.

Swan said that this study cannot prove that these boys will have fertility problems as adults or that DEHP causes these problems. However, animal studies have implicated the chemical in male reproductive problems. Based on the data from this study, Swan believes there is a strong association between exposure to DEHP and fertility in human males.

DEHP is used to soften plastics. Most exposure results from eating foods that pick up the chemical during processing, Swan said. "Since food is the largest source of DEHP for consumers, it is difficult for pregnant women to minimize exposure," she said. "Eating unprocessed food will likely help. However, eliminating DEHP from food really has to be done by food producers."The chemical is also found in medical tubing and in a variety of products, including flooring, wallpaper, lacquers and personal care products, Swan said.

For the study, Swan's team collected data on almost 800 pregnant women and their infants.Specifically, the researchers found that exposure in the womb to three types of DEHP was associated with a significantly shorter anogenital distance in boys, but not in girls.

A group representing the chemical industry took issue with the study, however. In a statement, the American Chemistry Council (ACC) stressed that the study only examined one type of phthalate, not all versions of the chemical... The ACC added that DEHP "is known to break down into its metabolites within minutes after it enters the body. 

But another expert says phthalate exposure may not be benign. Dr. Kenneth Spaeth, director of the Occupational and Environmental Medicine Center at North Shore University Hospital in Manhasset, N.Y., said, "virtually everyone in the U.S. experiences continual exposure to phthalates."And, a number of studies have tied the chemicals with changes in developing fetuses. "Phthalates, in particular, have been shown in both human and animal studies to interfere with normal fetal development," he said.

This study supports what has been demonstrated before, that phthalate exposure in the first trimester is linked to male reproductive development, Spaeth said. "This study is an important step forward in establishing this effect because the study included a much larger number of individuals than prior studies and helps identify one particular agent, DEHP, as an important contributor to this effect," he said.Additionally, this study shows the importance of exposure in the first trimester as a critical window for the effect of phthalates on the male reproductive system. 

Since people have abandoned using iodized salt and started using kosher salt or sea  salts, iodine deficiency has increased (especially during pregnancy when iodine needs are greater). The medical journal The Lancet noted in 2008: "According to World Health Organization, in 2007, nearly 2 billion individuals had insufficient iodine intake, a third being of school age. ... Thus iodine deficiency, as the single greatest preventable cause of mental retardation, is an important public-health problem." From Wikipedia : Iodine deficiency is the leading cause of preventable mental retardation, a result which occurs primarily when babies or small children are rendered hypothyroidic by a lack of the element. The addition of iodine to table salt has largely eliminated this problem in the wealthier nations. The article states that iodine deficiency typically lowers IQ by 10 to 15 points. So it's a big deal, a really big deal.  But don't overdo the iodine! Excess iodine also has serious problems.From Medscape:

New Recommendations Call for Iodine in All Prenatal Vitamins

Endocrinology groups are applauding a new recommendation from a dietary-supplement trade association that calls for iodine supplementation in all prenatal vitamins prescribed for pregnant and breastfeeding women.

In addition, the public health committee of the American Thyroid Association (ATA) recently published a statement reiterating the ATA recommendation that women take a daily multivitamin containing 150 μg of iodine during prepregnancy, pregnancy, and lactation. The statement also warns of the potential risks of excess iodine consumption and exposure, particularly through the use of unregulated kelp supplements.

The US Council for Responsible Medicine's new guidelines call for all dietary-supplement manufacturers and marketers to begin including at least 150 μg of iodine in all daily multivitamin/mineral supplements intended for pregnant and lactating women in the United States within the next 12 months.

In the past several years, removal of iodized salt from commercial products such as bread and milk, along with increased use of kosher salt and sea salt, which don't contain iodine, and the adoption of vegetarian and vegan diets have led to a reduction in dietary iodine consumption. "There never was a coherent US policy about iodization," Dr Stagnaro-Green noted.

Worldwide, about two billion people are iodine-deficient. While most of the US population has adequate iodine levels, data from the National Health and Nutrition Examination Survey suggest that more than half of pregnant women have urinary iodine concentrations below 150 mg/dL (Thyroid. 2011;21:419-427). 

Pregnant women actually need more iodine than other people because of increased thyroid-hormone production, renal losses, and fetal iodine requirements. Iodine deficiency during pregnancy can result in maternal and fetal goiter, cretinism, intellectual impairment, neonatal hypothyroidism, and increased pregnancy loss and mortality, Dr Stagnaro-Green and colleagues explained in a 2012 editorial (JAMA2012;308:2463-2464).

"So, women of childbearing age are the subpopulation of Americans with the lowest iodine levels yet have the greatest need during pregnancy and breastfeeding, for the neurodevelopment of the fetal and neonatal brain," he told Medscape Medical News. 

In 2009, a study found that only 51% of US prenatal multivitamin brands contained any iodine and, in a number of randomly selected brands, the actual dose of iodine contained in the supplements did not match values on the labeling.

However, the American College of Obstetricians and Gynecologists (ACOG) has not joined in these efforts. While the group does recommend the 150-μg dose for pregnant and lactating women, it does not currently endorse the prenatal-supplement recommendation, advising instead that women get their iodine through dietary sources.

In the ATA's public health committee statement, Angela M Leung, MD, from the University of California Los Angeles David Geffen School of Medicine, and colleagues, including Dr Stagnaro-Green, note that iodine is a micronutrient required for normal thyroid function. The US recommended daily allowances (RDA) for iodine intake are 150 μg in adults, 220 to 250 μg in pregnant women, and 250 to 290 μg in breastfeeding women. Dietary sources such as iodized salt, dairy products, some breads, and seafood usually contain enough to meet the RDA for most people who aren't pregnant or lactating.

However, there is an upper safety limit, with ingestion of more than 1100 μg/day not recommended due to the risk for thyroid dysfunction. In particular, infants, the elderly, pregnant and lactating women, and people with preexisting thyroid disease are at risk for adverse effects of excess iodine on the thyroid.

Many iodine, potassium iodide, and kelp supplements contain hundredfold greater amounts of iodine than the recommended upper limit, Leung and colleagues caution."Given the increasing popularity of iodine and kelp supplements, recommendations cautioning against excess iodine were indicated. The potential result of iodine-induced thyroid dysfunction, which may be particularly harmful during pregnancy and breastfeeding and in the elderly, may not be well-known," she told Medscape Medical News.

Another study that shows that differences in the gut microbiota appear early in life, and appear to be based on length of gestation (pregnancy) and type of delivery (vaginal vs C-section). From Science Daily:

Birth method, gestation duration may alter infants' gut microbiota

Environmental factors like mode of delivery and duration of gestation may affect how infants' gut bacteria mature, and that rate could help predict later body fat, international researchers have found.

Among a group of 75 infants, those who were vaginally delivered and had a longer gestation before birth tended to more quickly develop a more mature gut microbiota, and had typical body fat at 18 months. By contract, babies who were delivered via Caesarean section and had shorter gestations took longer to acquire a more mature gut microbiota and had lower body fat at 18 months.

"It seems like the early environment, for instance mode of delivery, mode of feeding, the duration of gestation and living environment may be influencing the rate at which babies acquire their gut microbiota," said senior study author Joanna Holbrook, a senior principal investigator at the Singapore Institute for Clinical Sciences, "and that in turn has an association with how babies grow and put on body fat."

At birth, human infants start accumulating intestinal microbiota until a relatively stable state is reached, Holbrook said. The rate at which babies acquire gut microbiota is believed to have a considerable impact on later health outcomes.

For the study, Holbrook and colleagues used a laboratory technique called 16s rRNA sequencing to analyze stool samples that had been collected from 75 infants participating in the GUSTO (Growing Up in Singapore Toward Healthy Outcomes) study, which includes members of the three main ethnic groups in Singapore: Chinese, Indian and Malay. The samples were taken when the infants were three days old, three weeks old, three months old and six months old. 

Their work found that the samples could be classified into three distinct clusters based on when infants' gut microbiota matured. Of 17 infants who had a more mature, six month-like microbiota profile high in the bacteria Bifidobacterium and Collinsella by day three, 16 were delivered vaginally. Other babies took up to six months to reach that stage.

Most infants acquired a similar microbiota by the age of six months. Infants that acquired a profile high in Bifidobacterium and Collinsella at an earlier age had typical body fat at age 18 months, while those that acquired this profile later had relatively low body fat.

Very important research looking at some professional football players who started playing tackle football before the age of 12, and comparing them to those who started later. It discusses the issue of whether children should be playing tackle football before the age of 12 - these and other results suggest NOT. Wait till older (or don't play tackle at all).This article came from Boston University through Futurity:

Is This Kid Too Young For Football?

Researchers from Boston University School of Medicine found that former National Football League (NFL) players who participated in tackle football before the age of 12 are more likely to have memory and thinking problems as adults.

The study contradicts conventional wisdom that children’s more plastic brains might recover from injury better than those of adults, and suggests that they may actually be more vulnerable to repeated head impacts, especially if injuries occur during a critical period of growth and development. "

“This is one study, with limitations,” adds study senior author Robert Stern, a professor of neurology, neurosurgery, and anatomy and neurobiology and director of the Alzheimer’s Disease Center’s Clinical Core. “But the findings support the idea that it may not make sense to allow children—at a time when their brain is rapidly developing—to be exposed to repetitive hits to the head.

In the study, researchers reexamined data from Boston University’s ongoing DETECT(Diagnosing and Evaluating Traumatic Encephalopathy Using Clinical Tests) study, which aims to develop methods of diagnosing chronic traumatic encephalopathy (CTE) during life. CTE is a neurodegenerative disease often found in professional football players, boxers, and other athletes who have a history of repetitive brain trauma. It can currently be diagnosed only by autopsy.

For this latest study, published in the journal Neurology, scientists examined test scores of 42 former NFL players, with an average age of 52, all of whom had experienced memory and thinking problems for at least six months. Half the players had played tackle football before age 12, and half had not. Significantly, the total number of concussions was similar between the two groups.

Researchers found that the players exposed to tackle football before age 12 had greater impairment in mental flexibility, memory, and intelligence—a 20 percent difference in some cases. These findings held up even after statistically removing the effects of the total number of years the participants played football. Both groups scored below average on many of the tests.

Stamm says the researchers were especially surprised by the scores on a reading test called the WRAT-4, which has participants read words of increasing difficulty....The low scores may be significant, she says, because they suggest that repeated head trauma at a young age might limit peak intelligence. She emphasizes, however, that there may be other reasons for a low score, and that more research is needed.

The authors chose age 12 as the cutoff because significant peaks in brain development occur in boys around that age. (This happens for girls a bit earlier, on average.) Around age 12, says Stern, blood flow to the brain increases, and brain structures such as the hippocampus, which is critical for memory, reach their highest volume.

Boys’ brains also reach a peak in their rate of myelination—the process in which the long tendrils of brain cells are coated with a fatty sheath, allowing neurons to communicate quickly and efficiently. Because of these developmental changes, Stern says, this age may possibly represent a “window of vulnerability,” when the brain may be especially sensitive to repeated trauma.

Stern adds that a study by another group of researchers of the number and severity of hits in football players aged 9 to 12, using accelerometers in helmets, found that players received an average of 240 high-magnitude hits per season, sometimes with a force similar to that experienced by high school and college players.

With approximately 4.8 million athletes playing youth football in the United States, the long-term consequences of brain injury represent a growing public health concern. This study comes at a time of increasing awareness of the dangers of concussions—and subconcussive hits—in youth sports like football, hockey, and soccer. In 2012, Pop Warner football, the oldest and largest youth football organization in the country, changed its rules to limit contact during practices and banned intentional head-to-head contact. 

“Football has the highest injury rate among team sports,” writes Christopher M. Filley, a fellow with the American Academy of Neurology, in an editorial accompanying the Neurology article. “Given that 70 percent of all football players in the United States are under the age of 14, and every child aged 9 to 12 can be exposed to 240 head impacts during a single football season, a better understanding of how these impacts may affect children’s brains is urgently needed.”

This study is important because it shows (once again) that spatial skills may be developed by what a child does in childhood. The trend for girls to only be given dolls or stereotypically "girl" toys is not that good for mental development (but good for nurturing). All children need to play with blocks, puzzles, and to create and build. They all need to go out and actively explore their environment, which also is good for developing spatial reasoning skills (as shown by earlier research). Think about it: when you actively explore the streets and land around you, you develop "mental maps" of how to get around, and this is good for spatial skills. Bottom line: encourage both boys and girls to build, create, do puzzles, play board games, and explore their outside environment. From Science Daily:

Playing with puzzles, blocks may build children's spatial skills

Play may seem like fun and games, but new research shows that specific kinds of play are actually associated with development of particular cognitive skills. Data from an American nationally representative study show that children who play frequently with puzzles, blocks, and board games tend to have better spatial reasoning ability.

"Our findings show that spatial play specifically is related to children's spatial reasoning skills," says psychological scientist and lead researcher Jamie Jirout of Rhodes College. "This is important because providing children with access to spatial play experiences could be a very easy way to boost spatial development, especially for children who typically have lower performance, such as girls and children from lower-income households."

Being able to reason about space, and how to manipulate objects in space, is a critical part of everyday life, helping us to navigate a busy street, put together a piece of "some assembly required" furniture, even load the dishwasher. And these skills are especially important for success in particular academic and professional domains, including science, technology, engineering, and math (STEM).

Jirout and Newcombe analyzed data from 847 children, ages 4 to 7, who had taken the revised WPPSI [Wechsler Preschool and Primary Scale of Intelligence], which included measures of cognitive skills that contribute to general intelligence. The children's spatial ability was specifically measured via the commonly-used Block Design subtest of the WPPSI, in which children are asked to reproduce specific 2D designs using cubes that have red, white, and half-red/half-white faces. The researchers also examined survey data from parents about the children's play behavior and joint parent-child activities.

The data revealed that family socioeconomic status, gender, and general intelligence scores were all associated with children's performance on the block design task. Children from the low-socioeconomic status group tended to have lower block design scores compared to children from either the middle- or high-socioeconomic status groups. And boys tended to have higher block design scores than did girls, though only after several other cognitive abilities, such as vocabulary, working memory, and processing speed, were taken into account.

Importantly, how often children played with certain toys was also tied to their spatial reasoning skills. Children who played with puzzles, blocks, and board games often (more than six times per week) had higher block design scores than did children who played with them sometimes (three to five times per week), or rarely/never.

None of the other types of play (e.g., drawing, playing with noise-making toys, and riding a bicycle, skateboard, or scooter) or the parent-child activities (e.g., teaching number skills, teaching shapes, playing math games, telling stories) included in the survey data were associated with children's spatial ability.

In line with previous findings, parents reported that boys engaged in spatial play -- playing with puzzles, blocks, and board games -- more often than girls, even after spatial ability was taken into account.

An amazing breakthrough for those suffering from peanut allergies. The bacteria Lactobacillus rhamnosus is added to some yogurts and kefir, but in smaller amounts.From The Telegraph:

Fatal peanut allergies could be cured by probiotic bacteria, say Australian doctors

A strain of probiotic bacteria could offer a cure for potentially fatal peanut allergies, according to scientists in Australia. The breakthrough followed a trial in which a group of children were given increasing amounts of peanut flour, along with a probiotic called Lactobacillus rhamnosus, over an 18-month period. About 80 per cent of the children who had peanut allergies were subsequently able to tolerate peanuts.

Mimi Tang, the lead researcher, said the families involved believed the treatment had "changed their lives". "These findings provide the vital first step towards developing a cure for peanut allergy and possibly for all food allergies," she told Melbourne's Herald Sun.

The randomised trial, involving a group of about 30 children, was conducted by Murdoch Childrens Research Institute in Melbourne. The children, aged one to ten, were given small amounts of peanut flour, gradually building up to two grams, or the equivalent of six or seven nuts.They were also given daily doses of Lactobacillus rhamnosus, which is found in yoghurt but was given in quantities equivalent to the amount found in 44 pounds of yoghurt.

Following the treatment, about 80 per cent of the children were able to tolerate four grams of peanut protein, equivalent to about 14 peanuts. Typically, about four per cent of children would have overcome their peanut allergy during this time.

Rates of peanut allergies have dramatically increased in the past two decades, particularly in developed countries. For most sufferers, the condition is lifelong.

A link to the press release from the Murdoch Childrens Research Institute (their researchers are doing the research), has more:

Oral Therapy Could Provide Treatment For Peanut Allergies

Over 60 peanut allergic children in the study were either given a dose of a probiotic, Lactobacillus rhamnosus, together with peanut protein in increasing amounts, or a placebo over 18 months to assess whether children would become tolerant to peanut.

The probiotic was a fixed daily dose, while the peanut oral immunotherapy was a daily dose of peanut protein starting at very low doses followed by a dose increase every two weeks until the maintenance dose (2 grams peanut protein) was reached. At the end of the treatment, the child's ability to tolerate peanut was assessed by a peanut challenge performed two to five weeks after stopping treatment.

23 of 28 (82.1%) probiotic treated children and one of 28 (3.6%) placebo-treated children were able to include peanut in their diet at the end of the trial. The likelihood of success was high - if nine children were given probiotic and peanut therapy, seven would benefit.

The need for a curative treatment is greatest for peanut allergy since this is usually lifelong, and is the most common cause of fatality due to food induced anaphylaxis. Further research is now required to confirm whether patients can still tolerate peanut years after the study has finished.

This is so sad, but it's the new reality in the USA. Less discussed, but also problematic is the increase in early puberty in boys.The research as to causes is ongoing, but increasingly our exposure to chemicals, especially endocrine disruptors is suspected to be a cause. What to do? Once again: try to reduce exposure to plastics (ha!) by buying and storing food in glass containers, and do not microwave food in plastic containers. Avoid fragrances or perfumed products. From Newsweek:

Puberty Comes Earlier and Earlier for Girls

At age 6, Rebecca’s body began to develop in ways that seemed unusual. Her mother, Ellen, had noticed a change in Rebecca’s breast area...But there was also the hair that had begun to appear under her daughter’s arms. When a test showed Rebecca’s bone age to be 10½, a pediatric endocrinologist diagnosed “precocious puberty.” While the exact cause is unknown, this endocrine disorder is triggered by the early release of hormones in the brain, a circumstance that hurls a child into sexual maturation years before the usual age.

This sudden sexual development in a child so young can be unnerving to parents. “My daughter is 7 years and 10 months old. She started having body odor at 5 and breast buds at 6,” one mother wrote recently in a group chat about the condition. She wrote, too, of her daughter’s “roller-coaster emotions,” a common complaint from parents observing massive mood swings, PMS-like symptoms and other “teen emotions” in daughters just beginning the first grade—and in some cases even younger. The condition affects individuals in different ways. ”...Unlike Rebecca, many precocious kids lose their interest in Disney and little-girl things and begin to act, well, the age of their bodies.

In girls, puberty is commonly defined as breast development, growth of pubic hair and menarche, the beginning of the menstrual cycle. At the turn of the 20th century, the average age for an American girl to get her period was 16 to 17. Today, that number has plummeted to less than 13, according to data from the National Health and Nutrition Examination Survey. The trend has been attributed to the epidemic of overweight children and a greater exposure to pollution, which does bad things to developing bodies and accelerates the timing of a girl’s first menstruation.

Environmental toxins also cause many girls to develop breasts at an earlier age than in the past. Compared with 20 years ago, American girls today begin developing breasts anywhere from one month to four months earlier, a significant difference. At the same time, the number of girls who begin to develop early is increasing. “Just a generation ago, less than five percent of girls started puberty before the age of 8; today that percentage has more than doubled,” note Dr. Louise Greenspan and Dr. Julianna Deardorff in The New Puberty: How to Navigate Early Development in Today’s Girls.

Among the toxins causing this trend, the biggest offenders are plastic compounds, in particular phthalates, man-made chemicals found all over the place: in plastic food and beverage containers, carpeting, shampoos, insect repellents, vinyl flooring, shower curtains, plastic toys and in the steering wheels and dashboards of most cars. Our bodies cannot metabolize phthalates, which interfere with the endocrine systemthe body’s system of glands and hormones—and harm fat cells. Indirectly, phthalates may cause weight gain and so influence the timing of puberty

Our children are living in a “sea of chemicals,” says Dr. Marcia E. Herman-Giddens, a professor of public health at the University of North Carolina. She argues that children are speeding into puberty before they’re ready, and that this early maturation is both the symptom of bodily damage that has already occurred and the probable cause of health consequences they may expect in the future.

Along with higher rates of depression, younger girls who enter puberty earlier than their peers are more prone to obesity and drug abuse...Meanwhile, no matter how physically developed a girl is, her psychosocial maturation remains anchored to her chronological age. 

“Puberty is considered one of those windows of susceptibility,” says Biro, when the body is especially sensitive to the negative health impact of social and environmental stressors. In particular, the actively maturing breast tissue of a girl, unlike the breast tissue of a full-grown woman, is more vulnerable to damaging environmental pollutants.

Today’s girl is both starting puberty earlier and going through it more slowly, according to Biro, which means a girl remains in this high-risk state for a longer amount of time. In an article he co-authored with Deardorff and others, Biro found up to a 30 percent increased risk for breast cancer when a woman experiences her first period at a younger age. And “for each year that age of menarche was delayed, the risk of premenopausal breast cancer was reduced by 9 percent, and risk of postmenopausal breast cancer was reduced by 4 percent.

Early breast development also opens the door to reproductive tract cancers, says Herman-Giddens, since “if you’re starting to develop breasts, your body is making estrogen.” Estrogen, especially when combined with stress hormones, is a known cancer-causing agent. Having had an earlier start to puberty, an early-maturing girl produces more estrogen over the years and so elevates her lifetime risk of reproductive cancers.

There is a medical solution for patients who, like 6-year-old Rebecca, are diagnosed with precocious puberty. Hormone treatments can essentially halt the process of sexual maturation. Then, at an appropriate age, the drugs are withdrawn and puberty plays out.Some girls diagnosed with precocious puberty have no choice but to medicate in order to prevent serious bone and growth problems

The evidence keeps growing of health effects with BPA exposure, especially during pregnancy and childhood. To minimize BPA exposure try to use glass instead of plastic. Try to drink from and store liquids in glass containers, and do not microwave food in plastic dishes. From Medical Daily:

BPA Disrupts Sperm Production In Mice, Could Be Linked To Decreased Fertility In Men

BPA, or bisphenol A, is a chemical component of plastic that is often found in plastic food containers, plastic bottles, and thermal receipts. Now, a new study shows a direct link between this chemical and disrupted sperm production in mice. BPA disrupts the delicate DNA interactions needed to create sperm, say the Washington State University researchers.

Sperm counts have declined over the past few decades worldwide, scientists warn. In Denmark, more than 40 percent of young men have sperm counts in the infertility or decreased fertility range. Reports from other European countries, Japan, and the United States all tell the same story. Sperm counts, though, may be only the tip of the iceberg. Studies also document an increase in abnormalities of male reproductive organs, including undescended testicles, hypospadias (when the urethra opening is misplaced on the penis), and increased incidence of testicular cancer — a constellation of male disorders referred to as testicular dysgenesis syndrome. This syndrome is thought to result from exposure, during early development, to estrogens. BPA is an endocrine disrupting chemical with estrogenic activity. Could descending sperm counts and testicular dysgenesis syndrome be linked to early exposures to this chemical?

Hunt and her colleagues gave newborn male mice oral doses of BPA. They also exposed another group of mice to the synthetic estrogen, ethinyl estradiol, which is used in many formulations of hormonal contraceptives (such as birth control pills). They also exposed another group of mice to a placebo. ..The team discovered that the sperm of BPA exposed mice did a poorer job of meiosis, the process by which cells combine the genetic information of their parents. As a result, more sperm died."We have a window of just a few days and we permanently change the way that the testis makes sperm in the adult," says Hunt.Hunt worries that sperm counts will continue to go down with each exposed generation. 

Same study, but this write-up has more background. From Environmental Health News:

BPA exposure linked to changes in stem cells, lower sperm production

The study, published online today in PLoS Genetics, is the first to suggest that low, brief exposures to bisphenol-A, or other estrogens such as those used in birth control but found as water contaminants, early in life can alter the stem cells responsible for producing sperm later in life...These exposures – comparable to human exposures to the compounds -- caused “permanent alterations” to the stem cells responsible for sperm production, the authors wrote.

Nice write-up of how what happens from the type of birth (vaginal vs cesarean) affects the baby's microbiome (community of microbes). Remember, it is very complicated and much is still unknown. (UPDATE: see January 16, 2015 post discussing research by Dr. Dominguez-Bello who is conducting a study in which babies born via C-section are immediately swabbed with their mother's vaginal secretions; these babies will then be followed for years). From Gastroenterology and Endoscopy News:

Delivery Mode Alters Newborn’s First Bacterial Exposure

 A baby’s first exposure to bacteria varies by the method of delivery, researchers have found. These differences could have health implications later in life, according to an emerging body of evidence that suggests gut bacteria may be important to the development of a healthy immune system (Arrieta MC et al.Front Immunol 2014;5:427). For example, evidence shows that alterations in gut bacteria early in life may increase the incidence of allergies later on (Bendiks M, Kopp MV. Curr Allergy Asthma Rep 2013;13:487-494).

In the new study, presented at the 2014 annual meeting of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition, a group at the University of Colorado School of Medicine, in Aurora, compared oropharyngeal aspirates taken from 12 infants born by cesarean delivery and 11 born vaginally, and their bacterial content by sequencing the bacterial genes in the samples (abstract 7). Samples taken from the mothers’ vaginal and rectal areas, and samples of the infants’ stool, were also analyzed for bacterial genes.

Bacteria in aspirates from newborns delivered vaginally were more similar to the bacteria found in samples from their mothers than the aspirates from infants born by cesarean delivery, the investigators found. Infants born vaginally had higher numbers of firmicutes (62.6% vs. 30.1%; P=0.0013), particularly lactobacilli typically found in the vagina.

Aspirates from infants born by cesarean delivery, in contrast, had higher levels of Actinobacteria (20.1% vs. 3.8%; P=0.045), which are found on the skin. Stool samples from vaginally delivered newborns also had greater numbers of Bacteroidetes than stool samples from infants born by cesarean delivery. This difference persisted through six weeks of life, the researchers said.

David Brumbaugh, MD, assistant professor of pediatrics at the University of Colorado School of Medicine, in Aurora, said the finding of fewer Bacteroidetes in cesarean newborns is potentially alarming. Studies of mice raised in sterile conditions have shown that exposure to a specific type of Bacteroidetes, Bacteroides fragilis, suppresses the animals’ inflammatory response (Mazmanian SK et al. Nature 2008;453:620-625), he said. 

“The fact that this bacteria never gets established early in life [in babies born by cesarean delivery] is concerning,” he said. Some studies have suggested that infants born by cesarean delivery may be at greater risk for developing conditions such as asthma, type 1 diabetes and celiac disease (Cho CE, Norman M. Am J Obstet Gynecol 2013;208:249-254). But not all studies have supported such risks; other studies suggest that genetic factors or the reason for the cesarean delivery itself may contribute to disease later in the child’s life (Almqvist C et al.Clin Exp Allergy 2012;42:1369-1376).

Jean-Eric Ghia, PhD, assistant professor of immunology and internal medicine at the University of Manitoba, in Winnipeg, Canada, said the findings add to a body of evidence suggesting that gut bacterial colonization is affected by mode of delivery, and these altered gut bacteria might contribute to immune system–related disease later in life (Neu J, Rushing J.Clin Perinatol 2011;38:321-331). “The first colonization of the gut happens when the baby comes out,” he said. But he noted that long-term studies are needed to assess the effect of these gut differences on health in the long term. He noted that a multitude of exposures before and after birth can also influence gut biota (Munyaka PM et al. Front Pediatr. doi:10.3389/fped.2014.00109 [published online October 9, 2014]). “It’s really, really complicated,” he said.

And the scary part is that they only tested for 32 chemicals, but there are thousands of others they didn't test for that could be lurking in the water, including pesticides used on the lawns and grounds around outdoor swimming pools. From Science Daily:

Pharmaceuticals, personal care products could taint swimming pools

A new study suggests pharmaceuticals and chemicals from personal care products end up in swimming pools, possibly interacting with chlorine to produce disinfection byproducts with unknown properties and health effects.

Chlorination is used primarily to prevent pathogenic microorganisms from growing. Previous research has shown that many constituents of urine including urea, uric acid, and amino acids, interact with chlorine to produce potentially hazardous disinfection byproducts in swimming pools. However, chemicals from pharmaceuticals and personal care products, or PPCPs, also could be interacting with chlorine, producing potentially harmful byproducts. There are literally thousands of chemicals from pharmaceuticals and personal care products that could be getting into swimming pool water.

A research group led by Ching-Hua Huang, a professor in the School of Civil and Environmental Engineering at the Georgia Institute of Technology, has developed an analytical technique that identifies and quantifies 32 pharmaceuticals and personal care products in water... Water samples were taken from indoor swimming pools in Indiana and Georgia.

Of the 32 chemicals investigated, the researchers detected three: N,N-diethyl-m-toluamide, known as DEET, the active ingredient in insect repellants; caffeine; and tri(2-chloroethyl)-phosphate (TCEP), a flame retardant.

"The other 29 could have been present at concentrations below the detection level," Blatchley said. "And because there are literally thousands of pharmaceuticals, this is just a small subset of compounds that could be present in swimming pools. The main issue is that the release of chemicals into a place like a swimming pool is completely uncontrolled and unknown. I don't want to be an alarmist. We haven't discovered anything that would be cause for alarm right now, but the bottom line is we just don't know."

Some chemicals are volatile, which means they can escape into the air to be inhaled. Others can be ingested or absorbed through the skin."Swimmers are exposed to chemicals through three different routes: You can inhale, you can ingest and it can go through your skin. So the exposure you receive in a swimming pool setting is potentially much more extensive than the exposure you would receive by just one route alone," Blatchley said.

His previous research has shown that certain airborne contaminants are created when chlorine reacts with sweat and urine in indoor swimming pools. Pharmaceuticals may get into swimming pool water from personal care products applied to the skin such as insect repellant, makeup and sunscreen. Many pharmaceuticals that are ingested are not fully metabolized by the body and are excreted in sweat and urine.

"Urine, I think, is really the primary mode of introduction," Blatchley said. "When it comes to pharmaceuticals, these are chemicals designed to be biologically active at pretty low concentrations. Birth control pills, for example, contain hormones. If those chemicals and others are present, especially in a mixture in a water sample that humans are going to be exposed to, then what are the consequences of that? That is a largely unanswered question."...The previous research suggested that about 93 percent of uric acid introduced to pools comes from human urine.