Impact of endocrine disrupting chemicals exposure on fecundity as measured by time to pregnancy

A systematic review;, Environmental research, 2018 Dec


Emerging scientific evidence suggests that exposure to environmental pollutants is associated with negative effects on fecundity as measured by time to pregnancy (TTP).

To conduct a systematic review of the literature on the association between selected endocrine disrupting chemicals (EDCs), and fecundity as measured by TTP in humans. Compounds included in this review are: brominated flame retardants (BFRs) such as hexabromocyclododecane, tetrabromobiphenol A and polybrominated diphenyl ethers; organophosphates flame retardants (OPFRs); and phthalates.

Scopus, MEDLINE via Ebscohost and EMBASE databases were searched for articles exploring the relationships between selected EDCs and fecundity as measured by time to pregnancy. We assessed the quality of included studies and evidence for causality was graded using the criteria developed by the World Cancer Research Fund.

14 studies of 191 full-text articles assessed for eligibility were included for qualitative synthesis. Five studies examined BFRs and 10 studies examined phthalates. Among the fourteen, one study assessed both BFRs and phthalates. There were no studies which investigated fecundity as measured by TTP on HBCD, TBBPA, or OPFRs. We recorded plausible fecundity outcomes as measured by TTP related to some of these EDCs. BFRs or phthalates increased TTP. However, results were inconsistent.

We recorded mostly weak associations between exposure to selected EDCs and fecundity. However, evidence was considered limited to conclude a causal relationship due to inconsistency of results. The health risks posed by these chemicals in exposed populations are only beginning to be recognized and prospective measurement of the environmental effects of the chemicals in large cohort studies are urgently needed to confirm these relationships and inform policies aimed at exposure prevention

Assessment of the biodegradability of selected sulfa drugs in two polluted rivers in Poland

Effects of seasonal variations, accidental contamination, turbidity and salinity

Up to 90% of consumed drugs enter the environment. This may have negative effects on wildlife, especially when the drugs take long periods to break down. This study assessed the breakdown of sulphonamides — a class of antibacterials — in samples from two rivers in Poland. The results showed that sulphamethoxazole, a common veterinary antibiotic, was the most persistent and that various factors inhibit degradation, including low temperatures, heavy metal pollution and low pH.


  • Biodegradation rate of sulfonamides (SNs) in river water is variable.
  • Biodegradability of SNs depends on the growing season.
  • High concentration of salts in river water inhibits the SNs biodegradation.
  • Sulfamethoxazole could be classified as Persistent Organic Pollutant (POP).


Which factors make drugs persistent? A look at sulphonamides in Polish rivers, Science for Environment Policy, 12 January 2017.

Assessment of the biodegradability of selected sulfa drugs in two polluted rivers in Poland: Effects of seasonal variations, accidental contamination, turbidity and salinity, science direct, August 2016.

Image credit Janusz Nowak.

The aim of our study was to assess the aerobic biodegradation of four selected sulfonamides (sulfanilamide, sulfamethoxazole, sulfadiazine and sulfathiazole) using water samples drawn from highly polluted rivers. Additionally, we aimed to identify the factors that have a significant effect on the process efficiency.

The 19 water samples were collected from Brynica and Czarna Przemsza rivers (in Poland) at the same location at approximately monthly intervals. A characteristic feature of the results is the presence of significant differences between the rates of sulfonamides biodegradation in particular samples.

The sulfonamide most resistant to biodegradation was sulfamethoxazole, whereas sulfathiazole was most biodegradable. Seasonal variations and related microbial population changes had the most significant effects on sulfonamides biodegradation, e.g., the studied process was highly inhibited during wintertime. A decrease in the biodegradation rate in the river water could be caused by an accidental water pollution by industrial wastewater with heavy metals, an increase in salinity and a decrease in pH, and turbidity.

The persistence of DDT and POPs chemicals contamination and the extinction risk for our wildlife

Extinction Risk for Many Species of Plants and Animals are Higher Than Suspected

A new study indicates that the number of plant and animal species at risk of extinction may be considerably higher than previously thought. A team of researchers, however, believe they’ve come up with a formula that will help paint a more accurate picture.

2017 Study Highlights

  • Range maps used by IUCN for threat assessment are inaccurate and mostly overestimated.
  • Citizen science, georeferenced ecological data, and distribution modeling allow accurate range estimates.
  • We found the ranges of 17 of 18 Western Ghats endemic bird species overestimated.
  • We also found 10 of those species requiring an uplisting of their IUCN threat status.
  • Methods used here to refine range estimates have conservation implications for taxa worldwide.


The validity of the threat status assigned to a species by the International Union for Conservation of Nature’s (IUCN) Red List relies heavily on the accuracy of the geographic range size estimate for that species. Range maps used to assess threat status often contain large areas of unsuitable habitat, thereby overestimating range and underestimating threat. In this study, we assessed 18 endemic birds of the Western Ghats to test the accuracy of the geographic range sizes used by the IUCN for their threat assessment.

Using independently reviewed data from the world’s largest citizen science database (eBird) within a species distribution modeling framework, our results show that:

  • geographic ranges have been vastly overestimated by IUCN for 17 of the 18 endemic bird species;
  • range maps used by IUCN contain large areas of unsuitable habitat,
  • and ranges estimated in this study suggest provisional uplisting of IUCN threat status for at least 10 of the 18 species based on area metrics used by the IUCN for threat assessment.

Since global range size is an important parameter for assigning IUCN threat status, citizen science datasets, high resolution and freely available geo-referenced ecological data, and the latest species distribution modeling techniques should be used to estimate and track changes in range extent whenever possible. The methods used here to significantly revise range estimates have important conservation management implications not only for endemic birds in the Western Ghats, but for vertebrate and invertebrate taxa worldwide.

Sources and Press Releases
  • IUCN greatly underestimates threat levels of endemic birds in the Western Ghats, science direct,, 26 April 2017.
  • Extinction risk for many species vastly underestimated, study suggests,, April 25, 2017.
  • Extinction Risk For Many Species Of Plants & Animals Are Higher Than Suspected, science times, Apr 30, 2017.
  • Image Credit: V. Ramesh et al. / Biological Conservation – The new models identified 10 species in need of potential uplisting on IUCN’s Red List. The white portion of pie chart shows percent suitable habitat within IUCN range, the blue portion shows percent of the range where unsuitable or no habitats are predicted.

Common veterinary antibiotics not quickly biodegradable infiltrate our aquatic environment

Which factors make drugs persistent? A look at sulphonamides in Polish rivers

Pharmaceutical pollution is a growing environmental concern in the EU, as the world’s second biggest consumer of human medicinal products. Up to 90% of orally administered drugs are excreted in the urine of animals and people1 , which means medicinal products can infiltrate the aquatic environment, where they may have negative effects on wildlife.

This study focused on sulphonamides, a group of chemicals used mainly as anti-bacterial agents. Although sulphonamides are now rarely used in human medicine, they remain important in animal medicine; in agriculture, up to 58 milligrams of sulphonamide can be used to produce just 1 kilogram of meat. As a result, levels of these drugs can reach 400 milligrams per kilogram in manure. The presence of these chemicals in the environment could promote drug resistance in bacteria in soil. After leaching into nearby water bodies, the drugs could also have negative impacts on aquatic organisms.

Which factors make drugs persistent? A look at sulphonamides in Polish rivers, Science for Environment Policy, 12 January 2017.

Assessment of the biodegradability of selected sulfa drugs in two polluted rivers in Poland: Effects of seasonal variations, accidental contamination, turbidity and salinity, science direct, August 2016.

Image credit PracticalCures.

Various factors are key to assessing the risk from a chemical, including its toxicological properties and how quickly it is broken down — the latter being the focus of this study. Chemicals that persist in the environment pose a risk because they can accumulate up the food chain, enabling them to reach potentially toxic levels. Some persistent chemicals can also move long distances, allowing them to travel far from their source.

According to the guidelines of the Stockholm Convention, substances with a half-life in the aquatic environment of over two months (i.e. it takes over two months for the chemical to break down to 50% of its original concentration) can be classified as persistent. Stockholm Convention parties, including the EU, are required to implement special procedures for such substances. Data suggest that the half-life of some sulphonamides is over two months, yet they are not considered persistent organic pollutants.

Many factors can affect the biodegradation rate of sulphonamides, such as the amount of light, the pH of the water and the presence of oxygen. This study investigated the biodegradability of four sulphonamides: sulphanilamide, sulpha-methoxazole, sulphadiazine and sulphathiazole. The researchers investigated the influence of weather conditions, water quality and experimental procedure on the breakdown of these sulphonamides in water samples collected from rivers in Poland.

A total of 19 water samples were collected from two highly polluted Polish rivers. Both rivers flow through one of the EU’s largest urban areas (the Upper Silesian Industrial Region), which has over 12 active coal mines and metallurgical industries and a human population of around 3 million. Immediately after sampling, a concentrated solution of sulphonamides was added to the water. The researchers quantified the concentration of the drugs in each sample over 28 days.

Before commencing biodegradation experiments, the researchers assessed the effect of sulphonamides on microorganisms in the water. After 18 hours of incubation, significant growth inhibition was observed, but after two days this inhibition decreased. This suggests that microorganisms are inhibited by the drugs but, over time, adapt to their presence.

Next, the researchers looked at how each drug was broken down by microbes (biodegraded). Microbial activity and thus biodegradation can depend on the effect of individual chemicals as well as external conditions such as temperature, leading to complex interactions.

Sulpha-methoxazole was the most resistant to biodegradation, with an average half-life of 72 days — meeting the definition of a persistent organic pollutant. As sulpha-methoxazole is the most commonly used sulphonamide in veterinary medicine and the most frequently detected in environmental samples, this result could be of environmental concern. Sulphathiazole was the most biodegradable, and had similar rates of biodegradation to the other two drugs, which were also rapidly broken down.

It is not only the type of sulphonamide that affects biodegradation. The researchers found that the factor with the biggest effect on biodegradation was temperature, with rates of breakdown significantly lower during the colder, winter season.

In Central European areas, vegetation increases with temperature from spring to autumn, leading to more biodiversity, higher microbial activity and a higher rate of biodegradation. However, during wintertime, temperatures drop and vegetation is suppressed, leading to reduced microbial activity and thus reduced biodegradation. This suggests the environmental risk associated with sulphonamides could be higher in the winter.

The authors also found a connection with pH, with acidity reducing degradation, and salt content (salinity), with higher salinity also reducing degradation (suggesting that removing salt from wastewater entering rivers could increase drug breakdown). Lower turbidity (the cloudiness of water, caused by particles it contains) also reduced breakdown, because the particles found in water support microorganisms. Finally, heavy-metal contamination from nearby industrial sites also inhibited sulphonamide degradation.

This study shows that various factors can reduce the biodegradation of sulphonamides and that risk may be particularly acute during winter, although further research is needed to clarify the ecological risk these compounds pose under different conditions

The dilemma in prioritizing chemicals for environmental analysis: known versus unknown hazards

Chemicals risk assessment: Baltic study recommends more monitoring of emerging pollutants

Chemicals are everywhere and new substances are regularly being introduced to the market. However, only some pose a risk to the environment. How do we decide which of them to monitor? A new study using a database of chemicals found in fish in the Baltic Sea has assessed which chemicals are commonly monitored. The researchers suggest that monitoring is biased towards known, already regulated hazardous chemicals, and recommend changes to address other chemicals.


The dilemma in prioritizing chemicals for environmental analysis: known versus unknown hazards, Royal Society of Chemistry, 05 May 2016.

Musa Bay, earthobservatory.nasa.

A major challenge for society is to manage the risks posed by the many chemicals continuously emitted to the environment. All chemicals in production and use cannot be monitored and science-based strategies for prioritization are essential.

In this study we review available data to investigate which substances are included in environmental monitoring programs and published research studies reporting analyses of chemicals in Baltic Sea fish between 2000 and 2012. Our aim is to contribute to the discussion of priority settings in environmental chemical monitoring and research, which is closely linked to chemical management. In total, 105 different substances or substance groups were analyzed in Baltic Sea fish. Polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) were the most studied substances or substance groups. The majority, 87%, of all analyses comprised 20% of the substances or substance groups, whereas 46 substance groups (44%) were analyzed only once. Almost three quarters of all analyses regarded a POP-substance (persistent organic pollutant).

These results demonstrate that the majority of analyses on environmental contaminants in Baltic Sea fish concern a small number of already regulated chemicals. Legacy pollutants such as POPs pose a high risk to the Baltic Sea due to their hazardous properties. Yet, there may be a risk that prioritizations for chemical analyses are biased based on the knowns of the past. Such biases may lead to society failing in identifying risks posed by yet unknown hazardous chemicals. Alternative and complementary ways to identify priority chemicals are needed. More transparent communication between risk assessments performed as part of the risk assessment process within REACH and monitoring programs, and information on chemicals contained in consumer articles, would offer ways to identify chemicals for environmental analysis.

Endocrine disrupting chemicals and uterine fibroids

Endocrine disruptors and reproductive disorders


Uterine fibroids are the most frequent gynecologic tumor, affecting 70% to 80% of women over their lifetime.

Although these tumors are benign, they can cause significant morbidity and may require invasive treatments such as myomectomy and hysterectomy.

Many risk factors for these tumors have been identified, including environmental exposures to endocrine-disrupting chemicals (EDCs) such as genistein and diethylstilbestrol.

Endocrine disrupting chemicals and uterine fibroids, Fertility and Sterility, Volume 106, Issue 4, Pages Pages 967–977, September 15, 2016.

“Feeling ill” image Maria Morri.

Uterine development may be a particularly sensitive window to environmental exposures, as some perinatal EDC exposures have been shown to increase tumorigenesis in both rodent models and human epidemiologic studies.

The mechanisms by which EDC exposures may increase tumorigenesis are still being elucidated, but epigenetic reprogramming of the developing uterus is an emerging hypothesis.

Given the remarkably high incidence of uterine fibroids and their significant impact on women’s health, understanding more about how prenatal exposures to EDCs (and other environmental agents) may increase fibroid risk could be key to developing prevention and treatment strategies in the future.

DES DiEthylStilbestrol Resources

Endocrine disrupting chemicals and endometriosis

Endocrine disruptors and reproductive disorders


Endometriosis is an estrogen dependent gynecologic disease with lasting implications for many women’s fertility, somatic health, and overall quality of life.

Growing evidence suggests that endocrine disrupting chemicals (EDCs) may be etiologically involved in the development and severity of disease.

We weigh the available human evidence focusing on EDCs and endometriosis, restricting to research that has individually quantified chemical concentrations for women, included a comparison group of unaffected women, and used multivariable analytic techniques.

Endocrine disrupting chemicals and endometriosis, Fertility and Sterility, Volume 106, Issue 4, Pages Pages 959–966, September 15, 2016.

laparoscopic surgery for endometriosis: fuschia_foot.

Evidence supporting an environmental etiology for endometriosis includes metals/trace elements, dioxins, and other persistent organic pollutants, as well as nonpersistent chemicals, such as benzophenones and phthalates.

To address the equivocal findings for various EDCs, future research directions for filling data gaps include

  1. use of integrated clinical and population sampling frameworks allowing for incorporation of new diagnostic modalities;
  2. the collection of various biologic media, including target tissues for quantifying exposures;
  3. study designs that offer various comparison groups to assess potentially shared etiologies with other gynecologic disorders;
  4. and novel laboratory and statistical approaches that fully explore all measured EDCs for the assessment of mixtures and low dose effects and the use of directed acyclic graphs, and supporting causal analysis for empirically delineating relationships between EDCs and endometriosis.

Chemicals risk assessment: more monitoring of emerging pollutants is needed

The dilemma in prioritizing chemicals for environmental analysis: known versus unknown hazards

Although chemicals have improved people’s quality of life in many ways, they have, in some cases, put the health of ecosystems and of people at risk. To protect the environment, the EU’s REACH regulation requires all substances for which over 1 tonne is produced in (or imported to) the EU every year to be registered. Under REACH, the hazards posed by registered substances to human health and the environment are evaluated, and restrictions on placing them on the market and on their use are imposed if appropriate.

In order to enable sound management of chemicals, with the aim of reducing the risks associated with their use, their effects in the environment should be known and their occurrence should be monitored. However, it is not feasible to do this for the millions of chemicals in use. It is, therefore, important to prioritise the chemicals of highest concern — a major challenge currently facing regulatory bodies.

Chemicals risk assessment: Baltic study recommends more monitoring of emerging pollutants, Science for Environment Policy, 02 September 2016.

Musa Bay, earthobservatory.nasa.

This study investigates how chemicals are prioritised for environmental analysis, using the Baltic Sea as a case study. The Baltic Sea is heavily polluted both by chemicals currently emitted, such as certain pharmaceuticals, and also by ‘legacy’ pollutants — i.e. pollutants released extensively years ago, but still of concern due to their persistence and hazardous properties.

To investigate which of these chemicals have been analysed (not specifically for regulatory purposes), the researchers looked at which chemicals were detected in Baltic Sea fish between 2000 and 2012. The focus on fish was for several reasons, including that contamination of fish in the Baltic Sea is a well-known and serious problem, which has led to restrictions on the European market in the trading of herring caught in the Baltic Sea, and that herring, a prominent fish species in the Baltic Sea, is very lipid rich, which facilitates the detection of organic pollutants in its tissue. The researchers collected data from screening programmes in Sweden, which borders the Baltic Sea, and from scientific journals.

In total, 105 different substances/groups of substances were analysed in Baltic Sea fish. The most studied substances were polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) (more commonly known as dioxins), and polychlorinated biphenyls (PCBs), another type of persistent organic pollutant (POP). POPs were by far the most studied substances; almost three quarters (72%) of all analyses were related to a POP-type substance. The majority (87%) of the analyses focused on the same 20% of substances, and almost half of substances were analysed only once.

Next, the researchers determined how many of these chemicals are regulated under the following:

  • Regulation EC 1272/2008 on classification, labelling and packaging (CLP) of substances and mixtures, which provides hazard information on chemicals.
  • The Stockholm Convention (Annexes A, B and C) — an international agreement to protect human health and the environment from POPs.
  • Regulation EC 1907/2006 concerning the registration, evaluation, authorisation and restriction of chemicals (REACH), which provides two important risk-management measures: authorisation and restriction:
  • Directive 2008/105/EC (as amended by Directive 2013/39/EU) on environmental quality standards (EQS). This Directive sets EQS in EU waters for a list of priority substances identified as posing a significant risk to the environment, or to human health via the environment, with the aim of achieving good chemical status.

More than two thirds of substances (70%) were covered by at least one regulation, or selfclassified by industry according to CLP environmental hazard criteria. Some of the nonregulated chemicals included certain metals, perfluorinated compounds (present in waterresistant materials and flame retardants), phenolic substances (widely used in industry) and phthalates (used to make plastics more flexible), although many chemicals in these groups are regulated.

Overall, the results show that the majority of analyses of fish in the Baltic Sea are focused on a small number of already regulated chemicals. Although regulated and some other known hazardous chemicals pose a high risk, the bias towards them could be diverting policymakers from identifying risks posed by other toxic chemicals.

The researchers suggest several ways of improving this situation, including using non-target screening techniques, such as chromatography combined with high-resolution mass spectrometry, which uses a more open-ended approach to screening for pollutants and can detect not only known hazardous chemicals (traditionally detected by using reference substances) but also potentially overlooked harmful chemicals. The researchers also recommend using biological tools, such as biomarkers, which measure the toxicity of chemicals via the physiological effects they have on organisms, such as effects on growth, reproduction or gene expression.

They also say that more open communication between regulatory activities, such as between risk assessment under REACH and monitoring under the Water Framework Directive, could be beneficial. Finally, they recommend that environmental agencies consider the chemicals contained in consumer products as emerging pollutants. They say these products are a major source of toxic substances, but are covered to a limited extent by current regulation.

European lakes contaminated with chemicals banned in the 1970s

Recent DDT and PCB contamination in the sediment and biota of the Como Bay

Research has found evidence for recent contamination of Lake Como, northern Italy, with chemicals banned in the EU since the 1970s. Levels of DDT and PCBs in sediment, aquatic microorganisms and fish were examined. The results suggest glacial meltwater as a source for renewed DDT contamination and show recent contamination of fish above safe levels. The findings demonstrate the need for continued monitoring of persistent organic pollutants in European waters.


Recent DDT and PCB contamination in the sediment and biota of the Como Bay (Lake Como, Italy), ScienceDirect, doi:10.1016/j.scitotenv.2015.10.099.
Como lake image by Jim.

Due to its peculiar geographical and morphological characteristics, Lake Como (Northern Italy) represents an interesting study-case for investigating the sub-basin scale circulation of persistent organic pollutants (POPs) that, despite being banned since the 1970s, have reached surprisingly high concentrations in some southern alpine lakes as a consequence of their release from melting glaciers in recent years. In particular, the Como Bay, which is located in the city of Como, seems noteworthy because its waters have a longer residence time than the other areas of the lake.

The analyses of the historical concentration of PCBs, pp′DDT and its metabolites in a sediment core sampled from the Como Bay covering a time-period from their ban to recent times, showed that the DDTs have never experienced a significant (p < 0.05) decrease over time, with concentrations of the most abundant homologue, pp′DDE, ranging from 27 to 75 ng g− 1 d.w. Conversely PCBs significantly (p < 0.05) decreased towards recent times, reaching concentrations around 80 ng g− 1 d.w. The contribution of high altitude and local sources was recorded also in the food web: both zooplankton and the zooplanktivorous fish agone were mainly contaminated by pp′DDE (81.4 ng g− 1 w.w. and 534.6 ng g− 1 w.w. respectively) and by the PCB metabolite hexa-CB (449.7 ng g− 1 w.w. and 1672.1 ng g− 1 w.w. respectively). The DDT concentrations in the agone (sampled during the years 2006–2009) never exceeded the limits for human consumption in Italy, while concentrations of six selected PCBs exceeded human health advisory recommendations in one of the fish samples analysed, when it was approximately two times higher than the recommended value of 125 ng g− 1.

Pesticide DDT linked to slow Metabolism, Obesity, Diabetes, Cholesterol and affected Offspring

Perinatal Exposure of Mice to the Pesticide DDT Impairs Energy Expenditure and Metabolism in Adult Female Offspring

As they reached adulthood, female mice who were exposed in utero and just after birth to the pesticide DDT showed metabolic changes that put them at greater risk for obesity, type-2 diabetes, high cholesterol and related conditions in female offspring later in life, a study led by the University of California, Davis, says.

DDT molecule
Pesticide DDT linked to an increased risk of obesity, diabetes, high cholesterol and related conditions in female offspring later in life – image Credit: © Zerbor / Fotolia.

Perinatal Exposure of Mice to the Pesticide DDT Impairs Energy Expenditure and Metabolism in Adult Female Offspring” is the first study to show that developmental exposure to DDT – like other persistent organic pollutants (POPs) – increases the risk of females later developing metabolic syndrome – a cluster of conditions that include increased body fat, blood glucose and cholesterol.


Dichlorodiphenyltrichloroethane (DDT) has been used extensively to control malaria, typhus, body lice and bubonic plague worldwide, until countries began restricting its use in the 1970s. Its use in malaria control continues in some countries according to recommendation by the World Health Organization. Individuals exposed to elevated levels of DDT and its metabolite dichlorodiphenyldichloroethylene (DDE) have an increased prevalence of diabetes and insulin resistance. Here we hypothesize that perinatal exposure to DDT disrupts metabolic programming leading to impaired metabolism in adult offspring. To test this, we administered DDT to C57BL/6J mice from gestational day 11.5 to postnatal day 5 and studied their metabolic phenotype at several ages up to nine months. Perinatal DDT exposure reduced core body temperature, impaired cold tolerance, decreased energy expenditure, and produced a transient early-life increase in body fat in female offspring. When challenged with a high fat diet for 12 weeks in adulthood, female offspring perinatally exposed to DDT developed glucose intolerance, hyperinsulinemia, dyslipidemia, and altered bile acid metabolism. Perinatal DDT exposure combined with high fat feeding in adulthood further impaired thermogenesis as evidenced by reductions in core temperature and in the expression of numerous RNA that promote thermogenesis and substrate utilization in the brown adipose tissue of adult female mice. These observations suggest that perinatal DDT exposure impairs thermogenesis and the metabolism of carbohydrates and lipids which may increase susceptibility to the metabolic syndrome in adult female offspring.

Sources and More Information
  • Pesticide DDT linked to slow metabolism, obesity and diabetes, UCDavis, news_detail.lasso?id=10982, July 30, 2014.
  • Perinatal Exposure of Mice to the Pesticide DDT Impairs Energy Expenditure and Metabolism in Adult Female Offspring, PLOS one, DOI: 10.1371/journal.pone.0103337, July 30, 2014.
  • Study says early DDT exposure may set up females for obesity, diabetes, LosAngelesTimes, Science, July 31, 2014.