Living near major roads linked to risk of dementia, Parkinson's, Alzheimer's and MS
January 23, 2020
Science Daily/University of British Columbia
Living near major roads or highways is linked to higher incidence of dementia, Parkinson's disease, Alzheimer's disease and multiple sclerosis (MS), suggests new research published this week in the journal Environmental Health.
Researchers from the University of British Columbia analyzed data for 678,000 adults in Metro Vancouver. They found that living less than 50 metres from a major road or less than 150 metres from a highway is associated with a higher risk of developing dementia, Parkinson's, Alzheimer's and MS -- likely due to increased exposure to air pollution.
The researchers also found that living near green spaces, like parks, has protective effects against developing these neurological disorders.
"For the first time, we have confirmed a link between air pollution and traffic proximity with a higher risk of dementia, Parkinson's, Alzheimer's and MS at the population level," says Weiran Yuchi, the study's lead author and a PhD candidate in the UBC school of population and public health. "The good news is that green spaces appear to have some protective effects in reducing the risk of developing one or more of these disorders. More research is needed, but our findings do suggest that urban planning efforts to increase accessibility to green spaces and to reduce motor vehicle traffic would be beneficial for neurological health."
Neurological disorders -- a term that describes a range of disorders, including Alzheimer's disease and other dementias, Parkinson's disease, multiple sclerosis and motor neuron diseases -- are increasingly recognized as one of the leading causes of death and disability worldwide. Little is known about the risk factors associated with neurological disorders, the majority of which are incurable and typically worsen over time.
For the study, researchers analyzed data for 678,000 adults between the ages of 45 and 84 who lived in Metro Vancouver from 1994 to 1998 and during a follow-up period from 1999 to 2003. They estimated individual exposures to road proximity, air pollution, noise and greenness at each person's residence using postal code data. During the follow-up period, the researchers identified 13,170 cases of non-Alzheimer's dementia, 4,201 cases of Parkinson's disease, 1,277 cases of Alzheimer's disease and 658 cases of MS.
For non-Alzheimer's dementia and Parkinson's disease specifically, living near major roads or a highway was associated with 14 per cent and seven per cent increased risk of both conditions, respectively. Due to relatively low numbers of Alzheimer's and MS cases in Metro Vancouver compared to non-Alzheimer's dementia and Parkinson's disease, the researchers did not identify associations between air pollution and increased risk of these two disorders. However, they are now analyzing Canada-wide data and are hopeful the larger dataset will provide more information on the effects of air pollution on Alzheimer's disease and MS.
When the researchers accounted for green space, they found the effect of air pollution on the neurological disorders was mitigated. The researchers suggest that this protective effect could be due to several factors.
"For people who are exposed to a higher level of green space, they are more likely to be physically active and may also have more social interactions," said Michael Brauer, the study's senior author and professor in the UBC school of population and public health. "There may even be benefits from just the visual aspects of vegetation."
Brauer added that the findings underscore the importance for city planners to ensure they incorporate greenery and parks when planning and developing residential neighbourhoods.
https://www.sciencedaily.com/releases/2020/01/200123152616.htm
High air pollution exposure in 1-year-olds linked to structural brain changes at age 12
January 24, 2020
Science Daily/Cincinnati Children's Hospital Medical Center
A new study suggests that significant early childhood exposure to traffic-related air pollution (TRAP) is associated with structural changes in the brain at the age of 12.
The Cincinnati Children's Hospital Medical Center study found that children with higher levels of TRAP exposure at birth had reductions at age 12 in gray matter volume and cortical thickness as compared to children with lower levels of exposure.
"The results of this study, though exploratory, suggest that where you live and the air you breathe can affect how your brain develops, says Travis Beckwith, PhD, a research fellow at Cincinnati Children's and lead author of the study. "While the percentage of loss is far less than what might be seen in a degenerative disease state, this loss may be enough to influence the development of various physical and mental processes."
Gray matter includes regions of the brain involved in motor control as well as sensory perception, such as seeing and hearing. Cortical thickness reflects the outer gray matter depth. The study found that specific regions in the frontal and parietal lobes and the cerebellum were affected with decreases on the order of 3 to 4 percent.
"If early life TRAP exposure irreversibly harms brain development, structural consequences could persist regardless of the time point for a subsequent examination," says Dr. Beckwith.
The researchers on the study, which is published online in PLOS One, used magnetic resonance imaging to obtain anatomical brain images from 147 12 year olds. These children are a subset of the Cincinnati Childhood Allergy and Air Pollution Study (CCAAPS), which recruited volunteers prior to the age of six months to examine early childhood exposure to TRAP and health outcomes.
The volunteers in the CCAAPS had either high or low levels of TRAP exposure during their first year of life. The researchers estimated exposure using an air sampling network of 27 sites in the Cincinnati area, and 24/7 sampling was conducted simultaneously at four or five sites over different seasons. Participating children and their caregivers completed clinic visits at ages 1, 2, 3, 4, 7 and 12.
Previous studies of TRAP suggest that it contributes to neurodegenerative diseases and neurodevelopmental disorders. This work supports that TRAP changes brain structure early in life.
https://www.sciencedaily.com/releases/2020/01/200124155107.htm
Mix of stress and air pollution may lead to cognitive difficulties in children
January 16, 2020
Science Daily/Columbia University's Mailman School of Public Health
Children with elevated exposure to early life stress in the home and elevated prenatal exposure to air pollution exhibited heightened symptoms of attention and thought problems, according to researchers at Columbia University Mailman School of Public Health and Columbia Psychiatry. Early life stress is common in youth from disadvantaged backgrounds who also often live in areas with greater exposure to air pollution.
Air pollution has negative effects on physical health, and recent work has begun to also show negative effects on mental health. Life stress, particularly early in life, is one of the best-known contributors to mental health problems. The new study is one of the first to examine the combined effects of air pollution and early life stress on school-age children. Results appear in the Journal of Child Psychology and Psychiatry.
"Prenatal exposure to polycyclic aromatic hydrocarbons, a neurotoxicant common in air pollution, seems to magnify or sustain the effects of early life social and economic stress on mental health in children," says first author David Pagliaccio, PhD, assistant professor of clinical neurobiology in psychiatry at Columbia Psychiatry.
"Air pollutants are common in our environment, particularly in cities, and given socioeconomic inequities and environmental injustice, children growing up in disadvantaged circumstances are more likely to experience both life stress and exposure to neurotoxic chemicals," says senior author Amy Margolis, PhD, assistant professor of medical psychology in psychiatry at Columbia Psychiatry.
"These exposures have a combined effect on poor mental health outcomes and point to the importance of public health programs that try to lessen exposure to these critical risk factors, to improve not only physical, but psychological health," says Julie Herbstman, PhD, associate professor of environmental health science and director of the Columbia Center for Children's Environmental Health at Columbia Mailman School of Public Health.
Data were from the CCCEH Mothers and Newborns longitudinal birth cohort study in Northern Manhattan and the Bronx, which includes many participants who self-identify as African American or Dominican. Mothers wore an air monitoring backpack during the third trimester of pregnancy to measure exposure to air pollutants in their daily lives. When their children were 5 years old, mothers reported on stress in their lives, including neighborhood quality, material hardship, intimate partner violence, perceived stress, lack of social support, and general distress levels. Mothers then reported on their child's psychiatric symptoms at ages 5, 7, 9 and 11.
The combined effect of air pollution and early life stress was seen across several measures of thought and attention problems/ADHD at age 11. (Thought problems included obsessive thoughts and behaviors or thoughts that others find strange.) The effects were also linked to PAH-DNA adducts -- a dose-sensitive marker of air pollution exposure.
The researchers say PAH and early life stress may serve as a "double hit" on shared biological pathways connected to attention and thought problems. Stress likely leads to wide-ranging changes in, for example, epigenetic expression, cortisol, inflammation, and brain structure and function. The mechanism underlying the effects of PAH is still being interrogated; however, alterations in brain structure and function represent possible shared mechanistic pathways.
Earlier studies making use of the same longitudinal cohort data found that prenatal exposure to air pollution combines with material hardship to significantly increase ADHD symptoms in children. A separate study found a combination of air pollution and poverty lowered child IQ.
https://www.sciencedaily.com/releases/2020/01/200116155436.htm
Air pollution in childhood linked to schizophrenia
January 7, 2020
Science Daily/Aarhus University
Air pollution affects physical health, and research results now conclude that it also affects our psychological health. The study, which combines genetic data from iPSYCH with air pollution data from the Department of Environmental Science, shows that children who are exposed to a high level of air pollution while growing up, have an increased risk of developing schizophrenia.
"The study shows that the higher the level of air pollution, the higher the risk of schizophrenia. For each 10 ?g/m3 (concentration of air pollution per cubic metre) increase in the daily average, the risk of schizophrenia increases by approximately twenty per cent. Children who are exposed to an average daily level above 25 ?g/m3 have an approx. sixty per cent greater risk of developing schizophrenia compared to those who are exposed to less than 10 ?g/m3," explains Senior Researcher Henriette Thisted Horsdal, who is behind the study.
To put these figures into perspective, the lifetime risk of developing schizophrenia is approximately two per cent, which equates to two out of a hundred people developing schizophrenia during their life. For people exposed to the lowest level of air pollution, the lifetime risk is just under two per cent, while the lifetime risk for those exposed to the highest level of air pollution is approx. three per cent.
Unknown cause
The results of the study have just been published in the scientific journal JAMA Network Open.
"The risk of developing schizophrenia is also higher if you have a higher genetic liability for the disease. Our data shows that these associations are independent of each other. The association between air pollution and schizophrenia cannot be explained by a higher genetic liability in people who grow up in areas with high levels of air pollution," says Henriette Thisted Horsdal about the study, which is the first of its kind to combine air pollution and genetics in relation to the risk of developing schizophrenia.
The study included 23,355 people in total, and of these, 3,531 developed schizophrenia. Though the results demonstrate an increased risk of schizophrenia when the level of air pollution during childhood increases, the researchers cannot comment on the cause. Instead they emphasise that further studies are needed before they can identify the cause of this association.
https://www.sciencedaily.com/releases/2020/01/200107104913.htm
Studies link air pollution to mental health issues in children
September 25, 2019
Science Daily/Cincinnati Children's Hospital Medical Center
Three new studies by scientists at Cincinnati Children's Hospital Medical Center, in collaboration with researchers at the University of Cincinnati, highlight the relationship between air pollution and mental health in children.
A study to be published Sept. 25 in Environmental Health Perspectives found that short-term exposure to ambient air pollution was associated with exacerbations of psychiatric disorders in children one to two days later, as marked by increased utilization of the Cincinnati Children's emergency department for psychiatric issues. The study also found that children living in disadvantaged neighborhoods may be more susceptible to the effects of air pollution compared to other children, especially for disorders related to anxiety and suicidality.
The lead authors of this study are Cole Brokamp, PhD, and Patrick Ryan, PhD. They are researchers in the division of Biostatistics and Epidemiology at Cincinnati Children's.
"This study is the first to show an association between daily outdoor air pollution levels and increased symptoms of psychiatric disorders, like anxiety and suicidality, in children," says Dr. Brokamp. "More research is needed to confirm these findings, but it could lead to new prevention strategies for children experiencing symptoms related to a psychiatric disorder. The fact that children living in high poverty neighborhoods experienced greater health effects of air pollution could mean that pollutant and neighborhood stressors can have synergistic effects on psychiatric symptom severity and frequency."
Two other Cincinnati Children's studies were recently published that also link air pollution to children's mental health:
· A study published in Environmental Research found an association between recent high traffic related air pollution (TRAP) exposure and higher generalized anxiety. The study is believed to be the first to use neuroimaging to link TRAP exposure, metabolic disturbances in the brain, and generalized anxiety symptoms among otherwise healthy children. The study found higher myoinositol concentrations in the brain -- a marker of the brain's neuroinflammatory response to TRAP.
· The lead authors of this study are Kelly Brunst, PhD, a researcher in the department of Environmental Health at the University of Cincinnati, and Kim Cecil, PhD, a researcher at Cincinnati Children's.
· A study published in Environmental Research found that exposure to TRAP during early life and across childhood was significantly associated with self-reported depression and anxiety symptoms in 12 year olds. Similar findings have been reported in adults, but research showing clear connections between TRAP exposure and mental health in children has been limited.
The lead authors of the study are Kimberly Yolton, PhD, director of research in the division of General and Community Pediatrics at Cincinnati Children's, and Dr. Ryan.
"Collectively, these studies contribute to the growing body of evidence that exposure to air pollution during early life and childhood may contribute to depression, anxiety, and other mental health problems in adolescence," says Dr. Ryan. "More research is needed to replicate these findings and uncover underlying mechanisms for these associations."
https://www.sciencedaily.com/releases/2019/09/190925075731.htm