written by Elise Miller, EdM
When many of us think of air pollution, images often come to mind of smoke stacks and diesel trucks spewing dirty fumes or thick brown smog enveloping cities. We think of people coughing or wearing masks on their faces to breathe, kids being rushed to emergency rooms for asthma attacks. These respiratory and lung conditions are of course part of our global reality today—and sadly so.
But I was truly struck by the plethora of new studies published during the last quarter implicating air pollution in a litany of other health outcomes. These conditions, not often associated with exposures to air particulates and other toxic airborne matter, include diabetes, autoimmune diseases, various forms of cancer, mental health, brain function, and birth defects. Nancy Hepp, CHE’s Research and Communications Specialist, compiled a long list of relevant studies (below) that appeared in journals and other media outlets from April through June 2015 highlighting these concerns.
Over the years, CHE has continued to make conscious choices about whether to bring attention to environmental contributors to specific health endpoints (such as diabetes or learning disabilities, which has been our traditional approach and the frame for our working group listservs) or to focus on a vector (like EMFs) or consider a particular set of chemical exposures (such as pesticides) or even a developmental phase (like children’s health or healthy aging). There are strong arguments to be made for implementing all of these different strategies at different times and different ways to help prevent disease and promote health.
For example, by targeting a vector like “air pollution”, we can potentially reduce multiple health problems as noted above. This is also an approach being used on a global scale. As discussed on CHE’s partnership call yesterday, “Towards a New Global Commission on Environmental Health“, environmental pollution can be far more deadly and disabling than many of the major infectious diseases of our time combined. To address this, investing more in reducing pollution in air, water, and food (often neglected by Heads of States and Health Ministers) could more widely benefit people’s health around the world, than simply working to eradicate a specific infectious disease such as HIV (which is of course an extremely worthy goal, but impacts fewer people than pollution does globally).
On the other hand, by framing an issue around a specific health endpoint, we also have an opportunity to improve the outcomes of other diseases and disabilities. For example, the pioneering work being done in Massachusetts to tackle high asthma rates (see: Massachusetts Strategic Plan for Asthma) is not just making sure everyone has access to inhalers, but includes steps to address a range of factors that all contribute to asthma—including reducing health disparities and toxic exposures as well as strengthening state-wide and local collaborative partnerships in the implementation process. (This is described in more detail on the recent podcast featuring Ted Schettler, MD, MPH, the science director for CHE and the Science and Environmental Health Network, and Polly Hoppin, CHE partner and Program Director for Environmental Health at the Lowell Center for Sustainable Production). Though this strategic plan is intended to lower asthma rates, it can also help reduce the incidence of other diseases, since we know toxic exposures and health disparities (for example) contribute significantly to other health problems too.
Reflecting on these different approaches affirms two important concepts that underlie CHE’s work:
- Using an ecological health model to understand how multiple, interacting factors and systems impact health is the most accurate framework to reflect the reality of our world—and though we may target one approach or another, ultimately we have to see every intervention in the context of this complex, systems-based model; and
- Implementing life-affirming interventions as far upstream as possible is most effective, but any positive action we can take—whether it’s eating a more nutritious diet or banning phthalates in flooring—can effect the whole system for good.
Whatever approach you’re taking this summer (including getting some rest and relaxation—an extremely important “intervention” on the individual level), may the ripple effects of your choices improve the health and well-being of all.
- Air pollution from road traffic and systemic inflammation in adults: a cross-sectional analysis in the European ESCAPE project: Living close to busy traffic was associated with increased CRP concentrations, a known risk factor for cardiovascular diseases. However, it remains unclear which specific air pollutants are responsible for the association.
- Increase in inflammation linked to high traffic pollution for people on insulin: People on insulin living next to roads with heavy traffic had markedly increased concentration of C-reactive protein, a marker of inflammation, compared to those living in lower traffic areas, a two-year epidemiological study has found. Individuals taking oral diabetes medications did not experience increases in CRP concentration. The study: Medication type modifies inflammatory response to traffic exposure in a population with type 2 diabetes
- Particulate air pollution exposure and expression of viral and human microRNAs in blood: the Beijing Truck Driver Air Pollution Study: Short-term EC exposure was associated with the expression of human and viral miRNAs that may influence immune responses and other biological pathways.
- Allergies/atopy/autoimmune diseases
- Air pollution fuels rise in allergies: study: The unexplained rise in allergies in recent decades may be tied to air pollution. That’s the conclusion of new research out of Canada that shows exposure to outdoor air pollution during the first year of life increases the risk of developing allergies to food, mold, pets, and pests. The study: Perinatal exposure to traffic-related air pollution and atopy at 1 year of age in a multi-center Canadian birth cohort study
- Fine particulate air pollution, nitrogen dioxide, and systemic autoimmune rheumatic disease in Calgary, Alberta: In this urban Canadian sample, adjusting for demographics, exposure to fine particulate was associated with an increased risk of systemic autoimmune rheumatic diseases. The results for nitrogen dioxide were inconclusive.
- Breast health:
- Long-term exposure to air pollution and mammographic density in the Danish Diet, Cancer and Health cohort: Traffic-related air pollution exposure does not increase mammographic density (MD), indicating that if air pollution increases breast cancer risk, it is not via MD.
- Cancer cases in Haifa Bay may be linked to air pollution, study finds: As existing data resurfaced in recent days potentially linking increased cancer incidence in the Haifa Bay to air pollution, Environmental Protection Ministry professionals said on Wednesday that they will recommend that their new minister declare the area “an air-pollution-stricken region.” The 2013 study: Organ specific cancer incidence in an industrial sub-district: a population-based study with 12 years follow-up
- Lung cancer and exposure to nitrogen dioxide and traffic: a systematic review and meta-analysis: The International Agency for Research on Cancer recently classified outdoor air pollution and particulate matter as carcinogenic (Group 1). These meta-analyses support this conclusion, drawing particular attention to traffic sourced air pollution.
- Vehicular traffic-related polycyclic aromatic hydrocarbon exposure and breast cancer incidence: the Long Island Breast Cancer Study Project (LIBCSP): In our population-based study, we observed positive associations between vehicular traffic-related benzo[a]pyrene (B[a]P) exposure and breast cancer incidence among women with comparatively high long-term traffic B[a]P exposures, although effect estimates were imprecise.
- Air pollution may cause more UK deaths than previously thought: Current figures of almost 30,000 UK deaths a year from air pollution do not factor in lethal nitrogen dioxide from diesel engines and wood, oil and coal burning, say experts.
- At least 1 in 6 dies early from fine dust: study: About 1 in 6 Koreans over age 30 have their lives cut short by air pollution, a study found Monday, raising concerns over public health.
- Low-concentration PM2.5 and mortality: estimating acute and chronic effects in a population-based study: Using a mutually adjusted model, we estimated significant acute and chronic effects of PM2.5 exposures below current EPA standards. These findings suggest that improving air quality below current standards may benefit public health.
- Pollution from ships kills thousands each year: Shipping emissions are an invisible killer that cause lung cancer and heart disease, a new study has found, but researchers say the 60,000 deaths they cause each year could be significantly cut by exhaust filtration devices. The study: Particulate matter from both heavy fuel oil and diesel fuel shipping emissions show strong biological effects on human lung cells at realistic and comparable in vitro exposure conditions
- Cleaner air would save two million lives a year: study: Cleaner air worldwide would save two million lives a year and not only in the most polluted countries, a study found. The study: Addressing global mortality from ambient PM2.5
- Air pollution kills 20,000 people a year in Mexico, report says: The report, titled “National Report on Air Quality in Mexico, 2013,” estimated that air pollution caused around 20,500 deaths in Mexico in 2010, with obstructive pulmonary chronic diseases, or OPCDs, ranking as the No. 8 cause of death.
- Mental health:
- Air pollution may be related to anxiety levels in women: study: The researchers found no link between anxiety levels and large air pollution particles, but exposure to fine particles was tied to increasing anxiety levels, according to results in BMJ. The study: The relation between past exposure to fine particulate air pollution and prevalent anxiety: observational cohort study
- Particulate air pollution and circulating biomarkers among type 2 diabetic mellitus patients: the roles of particle size and time windows of exposure: Results provided important evidence on the roles of the size and time windows of exposure in the PM-mediated effects on circulating biomarkers of inflammation, coagulation and vasoconstriction in diabetes patients in China.
- Maternal exposure to air pollution and type 1 diabetes—accounting for genetic factors: This study indicates that living in an area with elevated levels of air pollution during pregnancy may be a risk factor for offspring T1D.
- Ambient air pollution: an emerging risk factor for diabetes mellitus: This review summarizes recent findings from epidemiologic studies and mechanistic insights that provide links between exposure to air pollution and a heightened risk for diabetes.
- Association between ambient air pollution and diabetes mellitus in Europe and North America: systematic review and meta-analysis: Existing evidence indicates a positive association of air pollution and T2DM risk, albeit there is high risk of bias.
- Epidemiology of air pollution and diabetes: Here we review epidemiological studies aimed at answering whether diabetes patients are more vulnerable to ambient (outdoor) air pollution exposure and whether air pollution is associated with diabetes development or other predisposing conditions for type 2 diabetes.
- Long-term exposure to fine particulate matter and incidence of type 2 diabetes mellitus in a cohort study: effects of total and traffic-specific air pollution: Long-term exposure to total particulate matter (PM) increases type two diabetes risk in the general population, as does living close to a major road. Local traffic-specific PM was related to higher risks for type two diabetes than total PM.
- Brain function:
- Prenatal and childhood traffic-related pollution exposure and childhood cognition in the Project Viva cohort (Massachusetts, USA): Residential proximity to major roadways during gestation and early-life may affect cognitive development. Influences of pollutants and socioeconomic conditions on cognition may be difficult to disentangle.
- Ozone, particulate matter, and newly diagnosed Alzheimer’s disease: a population-based cohort study in Taiwan: These findings suggest long-term exposure to ozone and PM2.5 above the current US EPA standards are associated with increased risk of Alzheimer’s disease.
- Air pollution: long term exposure damages brain in older adults: Long-term exposure to air pollution can cause damage to brain structures and impair cognitive function in middle-aged and older adults, and put them at a 46% higher risk of silent strokes.
- Long-term PM2.5 exposure and neurological hospital admissions in the northeastern United States: To our knowledge, this is the first study to examine the relationship between long-term exposure to PM2.5 and time to the first hospitalization for the most common neurodegenerative diseases. We found strong evidence of an association for all three outcomes—dementia, Alzheimer’s and Parkinson’s diseases.
- Air pollution and impaired lung function prove independent risk factors for cognitive decline: “Our findings disprove the hypothesis that air pollution first decreases lung function and this decline, in turn, causes cognitive impairment by releasing stress signals and humoral mediators into the body,” explains Mohammad Vossoughi, a PhD student at the Leibniz (Germany) Institute for Environmental Medicine, who led the study.
- Air pollution may affect the way the brain ages and functions: The research indicates that older women who lived in geographic locations with higher levels of fine particulate matter in ambient air had significantly smaller white matter volumes across a wide range of brain areas. The study: Ambient air pollution and neurotoxicity on brain structure: evidence from Women’s Health Initiative Memory Study
- Birth outcomes:
- Air pollution causes low birth weight, Beijing study shows: The research surveyed the birth weights of 83,672 babies born in Beijing after the 2008 Olympics, when the government closed down industry, raised vehicle emissions standards, stopped construction and introduced a license plate rotation to slash the number of vehicles on the road. The study: Differences in birth weight associated with the 2008 Beijing Olympic air pollution reduction: results from a natural experiment
- Ambient air pollution and newborn size and adiposity at birth: differences by maternal ethnicity (the Born in Bradford Study cohort): Our results suggest that associations of ambient PM exposures with newborn size and adiposity differ between White British and Pakistani origin infants.
- Geographic variation in the association between ambient fine particulate matter (PM2.5) and term low birth weight in the United States: Our study provided additional evidence on the associations between PM2.5 exposure during pregnancy and term LBW from a national perspective. The magnitude and direction of the estimated associations between PM2.5 exposure and term LBW varied by geographic locations in the US. Environmental Health Perspectives.
- Elemental constituents of particulate matter and newborn’s size in eight European cohorts: Sulfur, reflecting secondary combustion particles in this study, may adversely affect term low birth weight and head circumference, independently of particle mass.
- Associations of pregnancy outcomes and PM2.5 in a national Canadian study: This study based on approximately 3 million births across Canada and employing PM2.5 estimates from a national spatiotemporal model provides further evidence linking PM2.5 and pregnancy outcomes.
- Autism spectrum disorder:
- Fine particulate matter and the risk of autism spectrum disorder.: Our data indicate that both prenatal and postnatal exposures to PM2.5 are associated with increased risk of ASD.
- Air pollution exposure during pregnancy and childhood autistic traits in four European population-based cohort studies: The ESCAPE Project: Prenatal exposure to nitrogen dioxide and particulate matter was not associated with autistic traits in children from four to ten years of age in four European population-based birth/child cohort studies.
- Blood pressure/cardiovascular health
- Short-term exposure to noise, fine particulate matter and nitrogen oxides on ambulatory blood pressure: a repeated-measure study: These findings suggest that exposure to noise and air pollutants may independently increase ambulatory blood pressure and the risk of cardiovascular diseases.
- A cross-sectional analysis of polycyclic aromatic hydrocarbons and diesel particulate matter exposures and hypertension among individuals of Mexican origin: This study builds on a limited number of prior investigations of the association between ambient air levels of PAHs or diesel particulate matter and hypertension by focusing on a relatively young cohort of predominantly adult women of Mexican origin.
- Use of the adaptive LASSO method to identify PM2.5 components associated with blood pressure in elderly men: the Veterans Affairs Normative Aging Study: Our study suggested exposure to ambient nickel was associated with increased blood pressure independent of PM2.5 mass in our study population of elderly men.
- Multiple diseases:
- Chronic disease prevalence in women and air pollution—a 30-year longitudinal cohort study: This study estimated significant elevated prevalent rate ratios per unit increase in PM2.5 in nine of the ten chronic diseases studied.
- Mexico City normal weight children exposed to high concentrations of ambient PM2.5 show high blood leptin and endothelin-1, vitamin D deficiency, and food reward hormone dysregulation versus low pollution controls. Relevance for obesity and Alzheimer disease: The changes found could signal the future trajectory of urban children towards the development of insulin resistance, obesity, type II diabetes, premature cardiovascular disease, addiction-like behavior, cognitive impairment and Alzheimer’s disease.
- Most effective air quality policies: a study of the past 20 years: There have been dramatic improvements in regional air quality across southern California over the past 20 years. Several key air pollutants, tracked by U.S. EPA, dramatically declined in outdoor concentrations between 1994 and 2011. The study: Emissions reduction policies and recent trends in Southern California’s ambient air quality
- A victory in the decades-long fight for environmental justice in the gulf and beyond: The Obama Administration and the EPA issued a much-needed, long-overdue public health safeguard that marks the beginning of the end of those regulatory loopholes in 38 states that have for decades allowed big polluters to dump huge amounts of off-the-books harmful air pollution onto neighboring communities with impunity.
- Air quality rules tightened after cancer risk found to be 3 times higher: Dozens of Southern California facilities, including oil refineries, aerospace plants and metal factories, will face new requirements to reduce toxic emissions or notify their neighbors of the health risks from their operations under rules approved by air quality officials.
- Dietary supplementation with olive oil or fish oil and vascular effects of concentrated ambient particulate matter exposure in human volunteers: Olive oil supplementation may be an efficacious intervention to protect against vascular effects of exposure to particulate matter.