Preterm birth associated with maternal fine particulate matter exposure

Millions of premature births could be linked to air pollution

Researchers for the Stockholm Environment Institute (SEI), the London School of Hygiene and Tropical Medicine and the University of Colorado, have concluded that as many as 3.4 million premature births across 183 countries could be associated with fine particulate matter, a common air pollutant, with sub-Saharan Africa, north Africa and south and east Asia most impacted by the issue.

Highlights

  • Ambient fine particulate matter (PM2.5) exposure is a possible risk factor for preterm birth.
  • We estimate 2.7–3.4 million preterm births may be associated with PM2.5 exposure in 2010 globally.
  • South/East Asia, North Africa/Middle East and West sub-Saharan Africa had largest burdens.
  • Maternal PM2.5 exposure should be considered alongside other preterm birth risk factors.

Abstract

Preterm birth associated with maternal fine particulate matter exposure: A global, regional and national assessment, sciencedirect, dx.doi.org/10.1016/j.envint.2017.01.023, 10 February 2017.

Millions of premature births could be linked to air pollution, study finds, the guardian, 16 February 2017.

Image credit Claude Robillard.

Reduction of preterm births (< 37 completed weeks of gestation) would substantially reduce neonatal and infant mortality, and deleterious health effects in survivors. Maternal fine particulate matter (PM2.5) exposure has been identified as a possible risk factor contributing to preterm birth. The aim of this study was to produce the first estimates of ambient PM2.5-associated preterm births for 183 individual countries and globally. To do this, national, population-weighted, annual average ambient PM2.5 concentration, preterm birth rate and number of livebirths were combined to calculate the number of PM2.5-associated preterm births in 2010 for 183 countries. Uncertainty was quantified using Monte-Carlo simulations, and analyses were undertaken to investigate the sensitivity of PM2.5-associated preterm birth estimates to assumptions about the shape of the concentration-response function at low and high PM2.5 exposures, inclusion of provider-initiated preterm births, and exposure to indoor air pollution.

Globally, in 2010, the number of PM2.5-associated preterm births was estimated as 2.7 million (1.8–3.5 million, 18% (12–24%) of total preterm births globally) with a low concentration cut-off (LCC) set at 10 μg m− 3, and 3.4 million (2.4–4.2 million, 23% (16–28%)) with a LCC of 4.3 μg m− 3. South and East Asia, North Africa/Middle East and West sub-Saharan Africa had the largest contribution to the global total, and the largest percentage of preterm births associated with PM2.5. Sensitivity analyses showed that PM2.5-associated preterm birth estimates were 24% lower when provider-initiated preterm births were excluded, 38–51% lower when risk was confined to the PM2.5 exposure range in the studies used to derive the effect estimate, and 56% lower when mothers who live in households that cook with solid fuels (and whose personal PM2.5 exposure is likely dominated by indoor air pollution) were excluded. The concentration-response function applied here derives from a meta-analysis of studies, most of which were conducted in the US and Europe, and its application to the areas of the world where we estimate the greatest effects on preterm births remains uncertain. Nevertheless, the substantial percentage of preterm births estimated to be associated with anthropogenic PM2.5 (18% (13%–24%) of total preterm births globally) indicates that reduction of maternal PM2.5 exposure through emission reduction strategies should be considered alongside mitigation of other risk factors associated with preterm births.

DEHP, DIBP, DBP and BBP chemicals identified as EDCs

Europe finally recognises four phthalates as human endocrine disruptors

Victory! First chemicals identified as EDCs to humans, Health and Environment Alliance Press Release, 17 February 2017.

Image Miljøstyrelsen.

Brussels, 17 February 2017 – In a historic development, four synthetic chemicals – DEHP, DIBP, DBP and BBP – have been identified as endocrine disrupting chemicals (EDCs) for human health. The news was first released by an official source in Denmark.

It means that for the first time, chemical substances have been included in the list of REACH substances of very high concern because of equivalent concern of “endocrine disrupting” properties in humans.

“We are very pleased that we’ve finally reached this historic moment: this is the first time that the EU REACH system is officially recognising chemicals as being of very high concern because of their endocrine disrupting properties to humans. The next major step is to put away the erroneous fiction that we can reliably establish ‘safe levels’ for endocrine disruptors – and then to regulate them accordingly.”

said Lisette van Vliet,
Senior Policy Adviser, Health and Environment Alliance (HEAL)

The decision came yesterday in an EU process known as “comitology”. One of the Member States in the forefront of advocating the official listing, Denmark, has been calling for proper regulation of these phthalates since 2011. Denmark is currently working with the European Chemicals Agency to propose a restriction that will ban these phthalates in products to which consumers come into contact, including products imported from outside the EU.

The phthalates are used as plasticisers in various products – from vinyl flooring to footballs and from wiring to shower curtains. Some of these products are made from recycled PVC, in which DEHP, one of the endocrine disruptors, has been authorised for use. The NGO Client Earth is contesting this authorisation in court, for multiple reasons, including that this substance is an endocrine disruptor for human health and the environment, which the REACH comitology committee has now confirmed.

The Diethylstilbestrol Legacy

A Powerful Case Against Intervention in Uncomplicated Pregnancy

2016 Report Abstract

Although the basic tenet of medicine is “First, do no harm,” history is filled with good intentions that were at best unhelpful and at worst harmful. Because medicine seeks to cure afflictions, there is an overwhelming desire on the part of health providers and patients to administer treatment. In certain settings, treatment can be reasonable despite a risk of adverse consequences: for example, if the disease is cured or its morbidity abated and the treatment consequences are less disabling than the disease itself.

In the absence of overt disease, the question of whether to apply an intervention is far more challenging. The safety of interventions must be weighed against the population’s level of risk, the morbidity and/or mortality associated with the disease, and the intervention’s efficacy (eg, BRCA1 mutation, mastectomy, reduced breast cancer risk). Interventions must meet an especially high standard of safety and efficacy when administered in low-risk populations or in settings in which the morbidity associated with the disease is minor. In the worst-case scenario, an intervention may be both ineffective for its primary purpose and cause iatrogenic illness.

The Diethylstilbestrol Legacy: A Powerful Case Against Intervention in Uncomplicated Pregnancy,
Pediatrics, November 2016, VOLUME 138 / ISSUE Supplement 1, Supplement_1/S42.abstract, November 2016.

Interventions in pregnancy are especially problematic because of the complex physiology of the condition and the possibility of causing short- and long-term adverse consequences in both the mother and her offspring. The continuing story of diethylstilbestrol (DES), a synthetic estrogen, shows the importance of caution when evaluating the merits of interventions involving pregnant women. With regard to DES, investigators believed that pregnancy loss was caused in part by a decrease in estrogen and that administering DES to pregnant women would help maintain a healthy pregnancy. Moreover, because endogenous estrogen concentrations increase dramatically during a healthy pregnancy, supplementation with DES was deemed harmless. During its early years of use, DES was administered to women with threatened pregnancy loss or a history of pregnancy loss. Eventually, DES was advertised to the medical community for “routine prophylaxis in ALL pregnancies” and administered to women with otherwise healthy pregnancies.

By the time DES was formally evaluated, it was standard of care in high-risk obstetrics practices. The first clinical trial to determine the efficacy of DES, reported in 1953, showed that DES did not improve pregnancy outcome. (Indeed, a subsequent reanalysis of the data revealed that DES increased the risk of spontaneous abortion, preterm birth, and neonatal death) Despite lack of evidence supporting a benefit, DES continued to be prescribed during pregnancy until 1971, when a small study showed a stunning 40-fold increase in the risk of clear cell adenocarcinoma (CCA) of the vagina and cervix in girls and young women who were prenatally exposed to DES. Several months later, the Food and Drug Administration issued a bulletin indicating that the use of DES was contraindicated in pregnancy. By then, however, millions of women, along with their sons and daughters, had been needlessly exposed.

In addition to the increased risk of CCA of the vagina and cervix, daughters exposed in utero to DES also suffered from an increased occurrence of reproductive tract abnormalities, infertility, and pregnancy complications; earlier menopause; twice the incidence of cervical dysplasia; and a possible elevated risk of breast cancer and continued increased risk of CCA in middle age. Recent preliminary data indicate the possibility of an increased risk of cardiovascular disease and diabetes in the prenatally exposed women. Mothers administered DES during pregnancy have an increased risk of breast cancer incidence and mortality. Sons who were exposed in utero have an increased risk of genitourinary defects and a possible increase in testicular cancer. The possibility of epigenetic transmission with consequent adverse outcomes in the offspring of prenatally exposed women is under investigation. Preliminary findings showed increased menstrual irregularity and a possible excess of ovarian cancer in very young women.

The link between prenatal DES exposure and subsequent adverse health outcomes, most of which are fairly common, may easily have escaped detection. The investigation of DES outcomes was initiated solely because a rare tumor occurred in a cluster of cases at an unusually young age, decades before the usual age of presentation. This historical example underscores the necessity of carefully weighing the risks and benefits of interventions in pregnancy and long-term monitoring of the health outcomes in mothers and offspring.

Whether and/or when to use pharmaceutical intervention in pregnancy continues to pose special challenges. At the present time, progesterone used to prevent pregnancy loss appears to be effective, although more data are needed. Thus far, there is little evidence of short-term adverse consequences for the offspring, but continued monitoring of mothers and offspring is warranted to identify any short- or long-term adverse effects. The use of progestins for luteal phase and early pregnancy support after in vitro fertilization is routine, and there are even fewer data on potential short- and long-term risks of this therapy. The tragic legacy of DES supports a cautious approach to the use of pregnancy interventions and assiduous appraisal of their effects.

Rebecca Troisi, Elizabeth E. Hatch, Linda Titus,
Reviewed by Dr Robert Hoover,

Click to download the full paper.

More DES DiEthylStilbestrol Resources

Cancer Risk in Women Exposed to Diethylstilbestrol in Utero

Significant increase of breast cancer in DES Daughters

2015 Study Abstract

OBJECTIVE
To evaluate the overall cancer risk, primarily breast cancer, for women exposed to diethylstilbestrol (DES) in utero in France.

METHODS
A cohort of 3 436 prenatally DES exposed women and a comparable cohort of 3256 unexposed women were recruited retrospectively from voluntary responses to questionnaires, and cases were ascertained by medical history at the time of recruitment.

Cancer Risk in Women Exposed to Diethylstilbestrol in Utero, US National Library of Medicine National Institutes of Health, Therapie, NCBI PubMed PMID: 26071143, 2015 Sep-Oct.

Image credit Amy the Nurse.

RESULTS
One hundred ninety-five cancers were observed in exposed women (136 breast cancers, and 59 in other sites) and 141 cancers in unexposed women (90 breast cancers, and 51 others). A significant increase of breast cancers was found in exposed women, with a multivariate incidence rate ratio of 2.10 (95% CI 1.60-2.76) when compared with unexposed women. When exposed women were compared with the general population in France, the standardized incidence ratio was 2.33 (95% CI 1.93-2.72).

CONCLUSION
Our results suggest a significant increase of breast cancer in prenatally DES exposed women when compared with unexposed women and with the general population. For other cancers, except clear cell carcinoma of the cervix or vagina, there was a global non-significant increase.

More DES DiEthylStilbestrol Resources

Personal Care Products

Are your PCPs really Safe?

Sources

Endocrine Disruptors

Comment évaluer les perturbateurs endocriniens et faire face à ce risque émergent ?

Par Véronique Le Tilly, Docteur en Biologie et Maître de conférences à l’ Universités Bretagne Sud

Vidéo publiée le 09/02/2017 par Université Bretagne Sud.

Merci à Véronique Le Tilly de mentionner le DES, Distilbene – 22:10 à 24:35 – et ses effets multiples sur plusieurs générations.

Les perturbateurs endocriniens sont au cœur d’une polémique qui fait rage entre industriels et consommateurs, comme souvent quand une question de santé publique est posée : en décembre 2015 la Cour de justice européenne condamne la Commission européenne pour ne pas avoir cadré réglementairement cette classe de polluants ; en octobre 2016, un sénateur morbihannais interpelle la Ministre de la Santé sur le scandale des muesli aux fruits non bio.

Les perturbateurs endocriniens sont partout. Présents dans nos aliments, nos produits cosmétiques, nos emballages, nos eaux de surface et le volant de notre voiture, ils sont partout ! Pour mieux comprendre la nature de ce risque biologique, nous parlerons dose, mécanismes et voies d’exposition, effets cocktail et bien sûr moyens d’évaluation.
Notre laboratoire a mis au point un test d’évaluation de ce risque. Peut-il aider à une évolution des pratiques et à la prise en compte progressive de ce risque ?

Sur le même sujet

Le Distilbène, Perturbateur Endocrinien

Flame retardant toxic chemicals are showing up in more people

Dramatic Rise in Flame Retardant Levels in Kids and Adults

Levels of a cancer-causing flame retardant are increasing dramatically in the bodies of American adults and children, according to a new studyTemporal Trends in Exposure to Organophosphate Flame Retardants in the United States – led by Duke University scientists, in collaboration with researchers at EWG and other universities.

2017 Study Abstract

During the past decade, use of organophosphate compounds as flame retardants and plasticizers has increased. Numerous studies investigating biomarkers (i.e., urinary metabolites) demonstrate ubiquitous human exposure and suggest that human exposure may be increasing.

To formally assess temporal trends, we combined data from 14 U.S. epidemiologic studies for which our laboratory group previously assessed exposure to two commonly used organophosphate compounds, tris (1,3-dichloro-2-propyl) phosphate (TDCIPP) and triphenyl phosphate (TPHP). Using individual-level data and samples collected between 2002 and 2015, we assessed temporal and seasonal trends in urinary bis (1,3-dichloro-2-propyl) phosphate (BDCIPP) and diphenyl phosphate (DPHP), the metabolites of TDCIPP and TPHP, respectively.

  • Data suggest that BDCIPP concentrations have increased dramatically since 2002. Samples collected in 2014 and 2015 had BDCIPP concentrations that were more than 15 times higher than those collected in 2002 and 2003 (10β = 16.5; 95% confidence interval from 9.64 to 28.3).
  • Our results also demonstrate significant increases in DPHP levels; however, increases were much smaller than for BDCIPP.
  • Additionally, results suggest that exposure varies seasonally, with significantly higher levels of exposure in summer for both TDCIPP and TPHP.

Given these increases, more research is needed to determine whether the levels of exposure experienced by the general population are related to adverse health outcomes.

Study and Press Releases

  • Temporal Trends in Exposure to Organophosphate Flame Retardants in the United States, American Chemical Society, DOI: 10.1021/acs.estlett.6b00475, February 8, 2017.
  • Dramatic Rise in Flame Retardant Levels in Kids and Adults, ewg News Releases, FEBRUARY 8, 2017.
  • Flame Retardant Chemicals Found in More People, consumer reports, February 13, 2017.

Early brain development in infants at high risk for autism spectrum disorder

Autism detectable in brain long before symptoms appear

At present, the earliest that children tend to be diagnosed for autism is at the age of two or later. A new study shows the origins of autism are in the first year of life. Could this lead to earlier tests and therapies while the brain is more malleable?

2017 Study Abstract

Brain enlargement has been observed in children with autism spectrum disorder (ASD), but the timing of this phenomenon, and the relationship between ASD and the appearance of behavioural symptoms, are unknown.

Retrospective head circumference and longitudinal brain volume studies of two-year olds followed up at four years of age have provided evidence that increased brain volume may emerge early in development.

Studies of infants at high familial risk of autism can provide insight into the early development of autism and have shown that characteristic social deficits in ASD emerge during the latter part of the first and in the second year of life.

These observations suggest that prospective brain-imaging studies of infants at high familial risk of ASD might identify early postnatal changes in brain volume that occur before an ASD diagnosis.

Early brain development in infants at high risk for autism spectrum disorder, nature, doi:10.1038/nature21369, 15 February 2017.

In this prospective neuroimaging study of 106 infants at high familial risk of ASD and 42 low-risk infants, we show that hyperexpansion of the cortical surface area between 6 and 12 months of age precedes brain volume overgrowth observed between 12 and 24 months in 15 high-risk infants who were diagnosed with autism at 24 months.

Brain volume overgrowth was linked to the emergence and severity of autistic social deficits. A deep-learning algorithm that primarily uses surface area information from magnetic resonance imaging of the brain of 6–12-month-old individuals predicted the diagnosis of autism in individual high-risk children at 24 months (with a positive predictive value of 81% and a sensitivity of 88%).

These findings demonstrate that early brain changes occur during the period in which autistic behaviours are first emerging.

The criteria to identify endocrine disruptors : implications beyond pesticides and biocides

NGOs call for single, unified system to identify hormone disruptors in cosmetics, water, children’s toys, and everywhere they appear

Original press release :
CIEL news.

Image credit : CIEL Facebook.

A single, unified system to identify hormone-harming chemicals is the best way to keep endocrine disrupting chemicals (EDCs) out of our food, water, toys, and household products.

This is the conclusion of a new report by the Center for International Environmental Law (CIEL) and ClientEarth, and endorsed by Members of the European Parliament (MEPs) from five parties.

Executive Summary

Endocrine Disrupting Chemicals (EDCs) are chemicals that interfere with the natural hormones in our bodies. EDCs are very likely to be contributing to serious health disorders such as cancer, fertility problems, obesity, and other debilitating diseases.

“The EU criteria to identify endocrine disruptors would be the first standards for these chemicals worldwide and set a precedent. The Commission must redesign the criteria to identify these hazardous substances wherever they are located.”

Giulia Carlini,
Staff Attorney at CIEL and co-author of the report.

EDCs are used in a wide variety of products. They are present in our food, cosmetics, clothes, cleaning products, and plastics.

The growing scientific evidence of their negative impacts and the wide exposure to them has led the EU legislator to mention, identify, and manage the risks from EDCs despite the lack of internationally harmonised criteria.

For the first time under EU law, the pesticides and biocides regulations both require the European Commission (the Commission) to determine the scientific criteria necessary to identify EDCs. These two regulations also provide for measure to control the risks from EDCs once identified.

Other regulations similarly contain provisions restricting the use of EDCs but have yet to provide identification criteria (e.g. the proposed regulations regarding medical devices). Still other regulations, such as the Regulation on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH), regulate EDCs as “substances of very high concern” on a case-by-case basis. In some cases, the law mentions EDCs without regulating their use, such as the Cosmetics Regulation or the Water Framework Directive.

“The Commission should look itself in the mirror and set out coherent criteria for identifying endocrine disruptors. These must work alongside other laws, for example on cosmetics, water, or chemicals in general.”

Vito Buonsante,
Law and Policy Adviser at ClientEarth and co-author of the report.

In June 2016, the European Commission proposed criteria for the identification of EDCs.

However, despite the variety of sources of exposure to EDCs, a mandate given to the Commission by the 7th Environmental Action Programme (7th EAP) to draft harmonised hazard-based criteria for EDCs, and seven years of work to establish these criteria, the European Commission chose a very narrow approach. It decided to set scientific criteria exclusive for relevant chemicals in pesticides and biocides.

The following report demonstrates that the Commission’s proposal is problematic and could:

  • Further delay the identification of EDCs and their proper regulation. Until horizontal criteria are developed as stipulated in the 7th EAP, EDCs cannot be regulated under other legislation. This is also at odds with the founding principles of Better Regulation, which aim at ensuring that the EU delivers high quality legislation.
  • Lower the level of protection from EDCs due to the misapplication of criteria relevant for biocides and pesticides to other regulatory frameworks. Applying sector-specific criteria to non-pesticides and biocides creates a risk that certain chemicals will not be identified as EDCs.
  • Lead to inconsistencies between the EDCs identified under the Pesticides and Biocides Regulations and those identified under other regulatory frameworks. The consequences of such approach may lead to a lower level of protection from EDCs, particularly for uses in consumer products (e.g. cosmetics, food contact materials, and toys).
  • Create an unclear, unstable, and unpredictable regulatory framework for businesses, workers, and citizens for as long as the scientific criteria are not applicable to chemicals under all regulatory frameworks.

In light of these concerns, CIEL and ClientEarth recommend:

  • The Commission should amend its proposed draft criteria to ensure they are applicable across all relevant EU law. The new criteria must be designed to identify EDCs in whatever product they are used, irrespective of the sector. This means that no sector-specific notions such as “non-target organisms” should be used. It should also follow the methodology of hazard identification under the United Nations Globally Harmonised System of Classification and Labelling of Chemicals and the Classification, Labelling and Packaging Regulation by providing three hazard categories based on the differing strength of evidence: “known” (category 1A), “presumed” (category 1B), and “suspected” EDCs (category 2).
  • If the Commission refuses to change its approach and adopts the proposals, the European Parliament and the Council should reject them, in compliance with the regulatory procedure with scrutiny and the procedure applicable to delegated acts under Article 290(2) TFEU, respectively.
  • If the current sector-specific scientific criteria are nonetheless approved, the Commission must immediately begin review of the criteria to comply with the objective of setting harmonised EDC criteria by 2020, as provided by the 7th EAP.

Can non-daytime shifts and physically demanding jobs decrease women’s fertility?

Indeed : heavy lifting, shift work could affect women’s fertility

Women who lift heavy loads at work may experience decreased fertility, and the effect appears stronger among overweight or obese women and older women, according to a new study from Harvard T.H. Chan School of Public Health.

Working non-daytime work schedules may also decrease fertility, the researchers found. 

2017 Study Abstract

Objectives
To explore whether work schedules and physically demanding work were associated with markers of ovarian reserve and response.

Methods
This analysis included women (n=473 and n=313 for ovarian reserve and ovarian response analysis, respectively) enrolled in a prospective cohort study of couples presenting to an academic fertility centre (2004–2015). Information on occupational factors was collected on a take-home questionnaire, and reproductive outcomes were abstracted from electronic medical records. Generalised linear models and generalised linear mixed models were used to evaluate the associations.

Occupational factors and markers of ovarian reserve and response among women at a fertility centre, BMJ, dx.doi.org/10.1136/oemed-2016-103953, 6 February 2017.

Results
Women who reported lifting or moving heavy objects at work had 1.0 fewer total oocytes (p=0.08), 1.4 fewer mature oocytes (p=0.007) and 0.7 fewer antral follicles (p=0.06) compared with women who reported never lifting or moving heavy objects at work. The inverse association between heavy lifting and oocyte yield was stronger in women >37 years and with a Body Mass Index ≥25 kg/m2. Women who worked evening/night/rotating shifts had 2.3 (p<0.001) fewer mature oocytes, on average, compared with women who worked day-only shifts. None of the occupational exposures were associated with day 3 follicle-stimulating hormone or peak oestradiol levels.

Conclusions
Women working non-daytime shifts and those with physically demanding jobs had fewer mature oocytes retrieved after controlled ovarian hyperstimulation. Our results provide insight into possible mechanisms linking these occupational exposures with decreased fecundity.