Welcome to The Visible Embryo
The Visible Embryo Birth Spiral Navigation
Fetal Timeline--- -Maternal Timeline-----News-----Prescription Drugs in Pregnancy---- Pregnancy Calculator----Female Reproductive System

WHO International Clinical Trials Registry Platform

The World Health Organization (WHO) has a Web site to help researchers, doctors and patients obtain information on clinical trials.

Now you can search all such registers to identify clinical trial research around the world!




Pregnancy Timeline

Prescription Drug Effects on Pregnancy

Pregnancy Calculator

Female Reproductive System


Disclaimer: The Visible Embryo web site is provided for your general information only. The information contained on this site should not be treated as a substitute for medical, legal or other professional advice. Neither is The Visible Embryo responsible or liable for the contents of any websites of third parties which are listed on this site.

Content protected under a Creative Commons License.
No dirivative works may be made or used for commercial purposes.


Pregnancy Timeline by SemestersDevelopmental TimelineFertilizationFirst TrimesterSecond TrimesterThird TrimesterFirst Thin Layer of Skin AppearsEnd of Embryonic PeriodEnd of Embryonic PeriodFemale Reproductive SystemBeginning Cerebral HemispheresA Four Chambered HeartFirst Detectable Brain WavesThe Appearance of SomitesBasic Brain Structure in PlaceHeartbeat can be detectedHeartbeat can be detectedFinger and toe prints appearFinger and toe prints appearFetal sexual organs visibleBrown fat surrounds lymphatic systemBone marrow starts making blood cellsBone marrow starts making blood cellsInner Ear Bones HardenSensory brain waves begin to activateSensory brain waves begin to activateFetal liver is producing blood cellsBrain convolutions beginBrain convolutions beginImmune system beginningWhite fat begins to be madeHead may position into pelvisWhite fat begins to be madePeriod of rapid brain growthFull TermHead may position into pelvisImmune system beginningLungs begin to produce surfactant
CLICK ON weeks 0 - 40 and follow along every 2 weeks of fetal development

Developmental Biology - Pesticides

EPA Fails to Follow Landmark Law Protecting Children

The EPA has failed to add mandated children's health safety to limits on almost 90% of most common pesticides...

The landmark Food Quality Protection Act requires the Environmental Protection Agency (EPA) protect children's health by applying an extra margin of safety to legal limits for pesticides in food.

However, an investigation by the Environmental Working Group (EWG) published this week in Environmental Health, a peer-reviewed scientific journal, found the EPA has failed to add the mandated children's health safety factor to the allowable limits for almost 90 percent of the most common pesticides.
The study in Environmental Health examined the EPA's risk assessments for 47 non-organophosphate pesticides since 2011, including those most commonly found on fresh fruits and vegetables, and found that the required additional tenfold safety factor was applied in only five cases.

"Given the potential health hazards of pesticides in our food, it is disturbing that the EPA has largely ignored the law's requirement to ensure adequate protection for children. The added safety factor is essential to protect children from pesticides that can cause harm to the nervous system, hormonal disruption and cancer," explains study author, Olga Naidenko PhD, Vice President for Science Investigations at EWG and author of the report.

The Food Quality Protection Act of 1996, or FQPA, requires the EPA to set allowable levels for pesticides in a way that would "ensure that there is a reasonable certainty that no harm will result to infants and children from aggregate exposure to the pesticide chemical residue..." and was hailed as revolutionary recognition that children are more vulnerable to the effects of chemical pesticides than adults.
"Based on the strong consensus of the pediatric and the public health communities, the FQPA stated unequivocally that regulation of toxic pesticides must focus, first and foremost, on protecting infants and children. When the EPA fails to apply this principle, children may be exposed to levels of chemical pesticides that can profoundly harm their health."

Philip Landrigan MD, Pediatrician, Epidemiologist, and Director, Program in Global Public Health and the Common Good at Boston College.

Landrigan also chaired the committee that authored "Pesticides in the Diets of Infants and Children," a 1993 report from the National Academy of Sciences. The groundbreaking study led to the FQPA's passage with bipartisan support and the backing of both industry and environmentalists.
"The FQPA was a revolution in how we think about pesticides' effects on children, but it does no good if the EPA doesn't use it. It's not only necessary to protect kids' health, it's the law, and the EPA's failure to follow the law is an egregious betrayal of its responsibility."

Ken Cook, President, the Environmental Working Group (EWG). The Environmental Working Group is a nonprofit, non-partisan organization that empowers people to live healthier lives in a healthier environment. Through research, advocacy and unique education tools, EWG drives consumer choice and civic action.

Naidenko's study also examined EPA risk assessments for a particularly toxic class of pesticides called organophosphates, which act in the same way as nerve gases like sarin and are known to harm children's brains and nervous systems. Naidenko found that under the Obama administration, the tenfold children's health safety factor was proposed for all organophosphate insecticides.
In contrast, the EPA under the Trump administration has not proposed adding the FQPA safety factor to any of the four assessments of pyrethroid insecticides. Even after human epidemiological studies conducted in the United States and in Denmark, revealed exposure to pyrethroid insecticides is associated with increased risk of attention deficit hyperactivity disorder.

In 2017, the EPA reversed the Obama administration's FQPA determination for chlorpyrifos, the most widely used organophosphate pesticide in the U.S. Despite the Trump EPA's decision, in the wake of bans by Hawaii, California and New York, the main U.S. chlorpyrifos manufacturer recently announced it will stop making this chemical. It remains to be seen whether the Trump EPA will uphold the tenfold FQPA determination for the entire group of organophosphates.
The study also found the Trump EPA has proposed to increase by 2.6-fold the allowable exposure to the herbicide metolachlor.

The use of metolachlor has increased for the past decade. The U.S. Geological Survey reports more than 60 million pounds is sprayed annually.

Biomonitoring studies conducted by the Centers for Disease Control and Prevention and by independent researchers report the presence of multiple pesticides and their byproducts in the American population, including herbicides such as glyphosate and 2,4-D, the bee-killing neonicotinoid insecticides, organophosphate and pyrethroid insecticides, and fungicide metabolites.

The Food Quality Protection Act of 1996, or FQPA, required the Environmental Protection Agency to set allowable levels for pesticides in a way that would “ensure that there is a reasonable certainty that no harm will result to infants and children from aggregate exposure to the pesticide chemical residue.” The act stipulated that an additional tenfold margin of safety for pesticide risk assessments shall be applied to account for pre- and postnatal toxicity and for any data gaps regarding pesticide exposure and toxicity, unless there are reliable data to demonstrate that a different margin would be safe for infants and children.

To examine the implementation of the FQPA-mandated additional margin of safety, this analysis reviews 59 pesticide risk assessments published by the EPA between 2011 and 2019. The list includes 12 pesticides used in the largest amount in the U.S.; a group of 35 pesticides detected on fruits and vegetables; and 12 organophosphate pesticides. For the non-organophosphate pesticides reviewed here, the EPA applied an additional children’s health safety factor in 13% of acute dietary exposure scenarios and 12% of chronic dietary exposure scenarios. For incidental oral, dermal and inhalation exposures, additional FQPA factors were applied for 15, 31, and 41%, respectively, of the non-organophosphate pesticides, primarily due to data uncertainties. For the organophosphate pesticides as a group, a tenfold children’s health safety factor was proposed in 2015. Notably, in 2017 that decision was reversed for chlorpyrifos.

For the majority of pesticides reviewed in this study, the EPA did not apply an additional FQPA safety factor, missing an opportunity to fully use the FQPA authority for protecting children’s health.

Abdiasis M. Hussein, Yuliang Wang, Julie Mathieu, Lilyana Margaretha, Chaozhong Song, Daniel C. Jones, Christopher Cavanaugh, Jason W. Miklas, Elisabeth Mahen, Megan R. Showalter, Walter L. Ruzzo, Oliver Fiehn, Carol B. Ware, C. Anthony Blau and Hannele Ruohola-Baker.

Return to top of page.

Feb 14 2020   Fetal Timeline   Maternal Timeline   News 

Chlorpyrifos is still on the market as an agricultural pesticide, routinely sprayed
on common crops like apples, oranges, strawberries and broccoli.
CREDIT Gerry Broome/Associated Press for the NYTimes

Phospholid by Wikipedia