Showing posts with label Urban Traffic. Show all posts
Showing posts with label Urban Traffic. Show all posts

Tuesday, February 28, 2017

Does Exposure to Traffic-Related Pollution Affect Dementia in Older Women?

Particulate air pollutants, APOE alleles and their contributions to cognitive impairment in older women and to amyloidogenesis in experimental models (8 page pdf, M Cacciottolo, X Wang, I Driscoll, N Woodward, A Saffari, J Reyes, M L Serre, W Vizuete, C Sioutas, T E Morgan, M Gatz, H C Chui, S A Shumaker, S M Resnick, M A Espeland, C E Finch and J C Chen, Translational Psychiatry, Jan. 31, 2017)

Also discussed here: Air pollution may cause 21 percent of dementias worldwide, study suggests (The San Diego Union-Tribune, Feb. 1, 2017)

And here: Early Onset Familial AD (Gabrielle Strobel, ALZFORUM)

Today we review research based on longer term exposure by female mice to PM 2.5 and how this could affect older women exposed to traffic-related air pollution in their risks of having dementia. Results indicate that women in the late 60s and 70s are 92% more likely to develop dementia if they live in areas that exceed EPA’s standards for PM2.5. The increase in the elderly and the greater risk of dementia has resulted in an overall increase in this disease, despite the improvements in levels of PM 2.5 over the last decade or two, as well as in the increase of deaths from Alzheimer’s, the sixth leading cause of death nationwide.

 dementia-alzheimers  

Key Quotes:

“Women aged 65 to 79 are 81 percent more at risk for general cognitive decline and 92 percent more likely to develop dementia if they live where fine particle matter exceeds the U.S. Environmental Agency’s standards”

“Cells in the brain treat these particles as invaders and react with inflammatory responses, which over the course of time, appear to exacerbate and promote Alzheimer’s disease,” “Since particles of this size are found in polluted air, the findings confirm recent evidence linking environmental factors, such as automotive-derived air pollution, to higher levels of dementia among people living near heavy traffic roads,”

“Residing in places with fine PM exceeding EPA standards increased the risks for global cognitive decline and all-cause dementia respectively by 81 and 92%,”

“ the evidence supports the schema that airborne PM accelerates neurodegenerative processes of ADRD through multiple pathways, including proamyloidogenic APP processing and other pathways independent of amyloid deposits.”

“We showed that nPM exposure increased both plaque formation and neurotoxic Aβ oligomers in cerebral cortex at 7 months (approximately equivalent to 35 years of human age, approaching peri-menopause). This implies that Aβ-dependent neurodegenerative processes in women with increased long-term PM exposure may precede cognitive declines or diagnosis of dementia, which is consistent with neuroimaging evidence for Aβ deposition even among cognitively intact individuals in their 50–60s.”

“As air pollution levels have been declining over the past 20 years, long-term exposure, especially during mid- or earlier life, may impart a greater risk”

Thursday, February 16, 2017

How is the Brain Damaged by Exposure to Traffic Related Air Pollution?

The Polluted Brain - Evidence Builds that Dirty Air Causes Alzheimer’s, Dementia (AAAS Science, Emily UnderwoodJan. 26, 2017) Also discussed here: Particulate Air Pollutants and White Matter Brain Aging (Abstract, Jiu-Chiuan Chen, Xinhui Wang, Mark A. Espeland, Helena Chui, Alzheimer’s and Dementia, Jul. 2014) And here: Traffic-related air pollution and brain development (21 page pdf, Nicholas Woodward, Caleb E. Finch and Todd E. Morgan , AIMS Environmental Science. May 6, 2015)

Today we review a series of research articles that reaffirm the health risks presented to people (and mice) who breathe in air polluted by vehicles and containing ultra-fine particles, in particular. Signs of memory loss and Alzheimer’s are evident in mice exposed to UFP. Levels of fine air particles within 50 m of major roadways are 10 times higher than at 150 m and those within 50 m stand a 12% higher risk of developing dementia. Tests involving prenatal mice showed that fetal damage can be done by fine particles without entering the placenta. The closer people live to major roadways, the smaller their celebral brain volume. What more do city planners and public health officials need to know about running highways and traffic through cities?

  brain-pollution  

Key Quotes:

“Typically smaller than 0.2 µm in diameter, these “ultrafine” particles fall within a broader class of air pollutants commonly referred to as PM2.5 because of their size, 2.5 µm or less. When it comes to toxicity, size matters: The smaller the particles that cells are exposed to.. the higher their levels of oxidative stress, marked by the production of chemically reactive molecules such as peroxides, which can damage DNA and other cellular structures”

“living in places with PM2.5 exposures higher than the Environmental Protection Agency’s (EPA’s) standard of 12 µg/m3 nearly doubled dementia risk in older women. If the finding holds up in the general population, air pollution could account for roughly 21% of dementia cases worldwide”

 “Neuroimaging and neuropathological studies have found that brain aging processes predominantly affect white matter (WM) in late life. Older people living in areas with high exposures to ambient particulate matter (PM) are more likely to have cognitive declines.”

“among 6.6 million people in the province of Ontario, those living within 50 meters of a major road—where levels of fine pollutants are often 10 times higher than just 150 meters away—were 12% more likely to develop dementia than people living more than 200 meters away. “

 “In mice that breathed the dirty air, they have found, the brain’s microglia release a flood of inflammatory molecules, including tumor necrosis factor a, which is elevated in the brains of people with Alzheimer’s disease and has been linked to memory loss. The pollution-exposed mice also showed other signs of brain damage,”

 “adverse health effects of air pollution exposure increase with closeness to major road… UFP <ultra-fine particles> was reduced by approximately 80% at a distance of 150 meters from the roadway..Neither PM2.5 nor PM10 decreased substantially within 150 meters …and are decreased by less than 20% at a distance of 400 m vs. 50 m from a roadway. The rate of dilution of UFP was correlated with increased cardiopulmonary mortality, inversely with distance from roadways”

“The placenta may be more vulnerable to nanoparticle entry later in gestation, when the placental wall has thinned and is more vascularized, but also early in gestation before the placenta is fully formed …The period after the placenta is formed, but before maternal-fetal circulatory systems are fully developed, could be less vulnerable to pollution exposure, due to minimal blood flow to the fetus. Nanoparticles may even cause fetal damage without penetrating the placenta, e.g. in vitro, nanoparticles can cause DNA damage even when they do not cross a cell barrier .. We note that these are not exclusionary hypotheses, and both may potentially be occurring. “

 “Traffic related air pollution is correlated with numerous detrimental health outcomes: increased cardiovascular mortality from adulthood exposures, and low birth weight and cognitive disorders from gestational exposure. These epidemiological observations are largely verified in animal models. “

 “the closer people had lived to a major roadway—and thus the more PM2.5 they had likely been exposed to—the smaller their cerebral brain volume. The association held up even after adjusting for factors such as education, smoking, diabetes, and cardiovascular disease.”

Tuesday, February 14, 2017

How Will We Get Around Town in 30 years and What Obstacles Need to be Overcome?

What will the local transport system look like in 2045? The future local transport system (David Levinson, Transportist, Dec.19, 2016)

 Also discussed here: What key factors do you see driving these changes over the next 30 years? (David Levinson, Transportist, Dec.19, 2016)

And here: Future Demand - New Zealand transport and society: Scenarios to 2042 (23 page pdf, New Zealand Government, Nov. 2014)

Today we review an interview on the future local transportation with Marcus Enoch by David Levinson and a report looking ahead to 2042 as part of New Zealand project PT2045. Enoch sees the automation of vehicles, their conversion to electric and the rise of shared mobility, as opposed to owning a vehicle, as the three most important changes. There will be a lot more single passenger, two wheeled e-cars and goods will be delivered by robot cars. Manually driven cars on public roads will be prohibited in 25 years. Urban congestion will end before 2042 with fewer, if any, private vehicles on the road. Carbon emissions will fall dramatically.

 nz-scenarios-for-2042  

Key Quotes:

“the most important change, will be the automation of vehicles – both private and public transport vehicles.” “The second most important change is the conversion of the vehicle fleet to being primarily electric.”

“The third change .. is the rise of shared mobility, mobility-as-a-service, where people won’t be owning cars, but instead will subscribe to a service, or buy the services on demand.”

“there will be a lot of single passenger vehicles. The best example I have is the Toyota iRoad vehicle, which is basically an enclosed motorcycle that’s safe and stabilised and, will, well before 2045, be automated. And it is safe because, not only is the vehicle designed well, with a roll bar and all that, but because all the other vehicles are also automated.”

 “there will be a substitution of logistic services for a lot of shopping trips, and we need to think about that. In urban areas the best model I have seen was a demo of using a small robot for delivering goods from stores to people’s homes”

“the political system is going to have to play catch up with the technological system, and legal system is also going to be playing catch up. ..Uber decided what service they were going to provide, and they did it illegally, and they got away with it” “From an economic perspective, at the point where it’s cheaper to provide an automated vehicle than it is to provide a manually driven vehicle, people will switch over.”

 “25 year timeframe is probably enough for the last manually driven car to be prohibited from driving on streets or public roads most of the time.”

 “Congestion is a thing of the past. Compared to 2014, fewer people can afford to travel across and between towns by private vehicle so many urban and regional roads are relatively free of private travellers. Inter-regional bus services have increased in popularity, connecting market towns to urban centres.”

“Compared to 2014, people are using all motorised forms of transport far less. People prefer exploring the digital world to travelling outside. Obesity and diabetes rates have increased because of a lack of physical exercise. People regularly try to manage their health by walking and cycling for recreation. Climate emissions from transport have fallen dramatically.”

Thursday, February 9, 2017

How Would Vancouver Transition to a Driverless City?

Turning Transportation Challenges and Opportunities Presented to the City of Vancouver by Autonomous Vehicles (93 page pdf, Cail Smith, Greenest City Scholars Report, Aug. 31, 2016)

Also discussed here: Vancouver Prepares For a Driverless Future That Includes Extra Space for Walking, Cycling, and Transit (Mobility, Jan. 17, 2017)

And here: Transportation 2040 Plan: A transportation vision for the City of Vancouver (City of Vancouver)

And here: Transportation 2040 (99 page pdf, Plan as adopted by Vancouver City Council, Oct.31, 2012)

Today we review plans and reports aimed at the future of Vancouver in 2040 which may include a transition to driverless or autonomous vehicles (AV) as well as meeting the target of having 2/3 of all trips made on foot, by bike or transit. With a 90% AV share, freeway congestion would be reduced by 60% from present levels and 30% of city traffic would be reduced by no need to search for parking. Garages could be converted to guest houses and garage lanes to useful parks or gardens. Shifting to AVs would save the average Canadian household $2,700 per year (4% of income) by decreasing insurance, fuel and parking costs, as well as saving the City of Vancouver $15 M/yr on maintaining and monitoring parking spots, while also reducing revenue from parking tickets by $53M/yr (also 4% of net revenue).

 driverless-vancouver  

Key Quotes:

 “We need to ensure we are proactive in meeting our Transportation 2040 goals, and whether there are policies in the City’s toolkit to help minimize the risks and pressures automated vehicles might put on those goals.”

“Transportation 2040 plan – passed unanimously by Council in October 2012 – is a key policy direction that explicitly prohibits a net increase in motor vehicle capacity on City of Vancouver streets. Once driverless dreams become a reality, this creates an exciting opportunity for building complete streets that include wider sidewalks, protected bike lanes, and bus rapid transit lines.”

“In the next 30 years, the number of Vancouver residents aged 60 and over will more than double. An aging population means changes in travel patterns and more people with physical challenges getting around our city”

 “In the City of Vancouver, vehicles account for over 30% of greenhouse gas emissions. We can make a big difference by prioritizing sustainable transportation choices that use renewable fuels or use fuels more efficiently (transit, ride-sharing, and low-carbon vehicles), or don’t use fuel at all (walking, cycling)”

 Some key targets:

“By 2040, at least two-thirds of all trips will be made on foot, bike, or transit. The total number of trips by sustainable modes will grow significantly, while motor vehicle volumes will slightly decline.”

 “By 2020, the average distance driven per resident is reduced by 20% (from 2007 levels)”

“Although the Telsa Model S and Google Car are both well - known as “driverless” vehicles, they have very different capabilities. The Model S is only at level 3 so when its ADAS systems are engaged, the driver must still be ready to intervene at anytime. On the other hand, the Google Car is closer to level 4 or 5 and the driver is not expected to monitor the vehicle.”

 “Industry experts suggests that by 2040, AVs will be the primary means of transport” “I was able to convert the garage in a laneway house for my mother-in-law. Our whole neighbourhood is doing something similar. Our back lane is a great public space.”

“There also might be significant changes to or the removal of traffic signals, traffic markings and signage designed to communicate with users piloting motor vehicles. Research is already being done on autonomous intersection management (AIM) where an intersection “server” Communicates directly with vehicles rather than through traffic lights”

“If AVs are able to reduce the space between vehicles in a lane,.. that with 90% AV market share, freeway congestion would be reduced to 60% of its current levels. Additionally, if AVs can drive in narrower lanes, road space can be reallocated for walking, cycling and transit paths.”

“The time and VKT spent searching for parking also has a significant impact on congestion in the city; some researchers estimate 30% of city traffic can be attributed to people searching for parking “

“Fewer parking spots will also reduce maintenance and monitoring costs (a $15,153,000 expense for the City in 2015) and also reduce the revenue generated from parking ($53,178,000 revenue in 2015, around 4% of total revenue).

“In Canada, the average private vehicle sits idle for over 23 hours per day and costs over $9,000 annually if driven regularly …Initial research indicates that switching to SAVs could save individual households an average of $2,700 per year (4% of the average household budget) by decreasing insurance, fuel and parking costs “

Thursday, February 2, 2017

How Does the Environment Affect Perceived Wait Times at Transit Stops?

Transit Stop Environments and Waiting Time Perception Impacts of Trees, Traffic Exposure, and Polluted Air (Abstract, Marina Lagune-ReutlerRelated information, Andrew GuthrieRelated information, Yingling FanRelated information, and David Levinson, Transportation Research Record: Journal of the Transportation Research Board, Jan. 9, 2017)

Also discussed here: Transit Riders’ Perception of Waiting Time and Stops, Surrounding Environments (17 page MS Word, Marina Lagune-Reutler, Andrew Guthrie, Yingling Fan, David Levinson, Draft submitted to Transportation Research Record: Journal of the Transportation Research Board, July 2015)

Today we review research based on over 800 responses from users of public transit in Minneapolis, MN. The key factor studied was the wait times –both real and perceived- and how this varied with the type of environment found at bus and transit stops. Results indicate that polluted air and the presence of heavy traffic near the stops tended to increase the length of perceived wait time when this was over 5 minutes while the presence of trees and light traffic shortened the perceived wait time. Conclusions and recommendations to encourage more transit use include locating transit lines away from traffic and heavily polluted areas and planting trees and foliage near the stops. Canadians and those in cold climates would be heartened by the finding that more or less snow has little effect on transit users who, if anything were more likely to happy they
  were not driving a private car.


transit-and-aq

 Key Quotes:

“research on pedestrian design finds that high-quality and natural environments reduce stress and encourage walking and bicycling. It seems reasonable that similar effects would apply for transit users on the basis of the environments around transit stops”

“For waits longer than 5 min, perceptible pollution and exposure to traffic led to significant overestimates of waiting time. Riders waiting at stops with dense, mature tree cover, however, significantly underestimated their waiting times”

 “regular riders have relatively lower burdens for waiting than occasional transit users. Passengers’ negative emotions such as anxiety, boredom or stress tend to increase time perception of time while distractions appear to reduce their wait time estimates”

“women perceive longer waiting time at stops or stations located in an unsafe environment:at a simple curbside bus stop, a 10 minute wait seems to take nearly half an hour.”

 “The effect of dense, mature tree cover is strong enough to compensate for the effects of both air pollution and traffic awareness”

“The results strongly support the research hypothesis that the surrounding environment of transit stops and stations affects transit user’s wait time perception. They show in particular that air pollution, traffic awareness, and presence of mature trees are significantly correlated with wait time perception.”

 “The effect of the snow cover is unexpectedly positive and shows that the weather does not affect negatively transit users’ time perception. Transit users may be happy about the fact they aren’t driving, and alternatively, transit users on such days may have a high tolerance for cold weather, due to self selection.”

 “the results suggest that the more trees are present, the shorter the wait time is perceived by riders while the more polluted and exposed to the traffic the more transit users tend to overestimate wait time. These findings advocate for high quality urban environment surrounding stops and stations.”

 “Creating exclusive transit lanes or streets reserved for transit, bicycles and pedestrians (where feasible) are likely to reduce waiting time perceptions the most, due to low traffic volumes in terms of vehicle frequency compared with automotive traffic.”

 “the alignment of transit routes and the location of stops avoiding highly polluted areas where possible without affecting travel demand can also contribute to shorter wait time especially when headways are greater than five minutes”

 “Planting trees around stops offers local authorities an opportunity to significantly improve users' wait time perception,”

Tuesday, January 31, 2017

Living Close to Traffic and the Risk of Dementia

Living close to major roads linked to small increase in dementia risk (Abstract, the Lancet, Jan.4, 2017)

Also discussed here: Living near major roads is associated with increased dementia risk, study finds (Susan Mayor, The British Medical Journal, Jan. 5, 2017)

And here: Living near major traffic linked to higher risk of dementia (Public Health Ontario, Jan. 4, 2017)

And here: Does Living by a Busy Road Boost Dementia Risk? Exposure to heavy traffic tied to cognitive decline (Alexandria Bachert , MedPage Today, Jan. 4, 2017)

Today we review a study with over 6.5 million people living in Ontario that examined the impact of living near high traffic roadways and the incidence of dementia, the first time such a study has been conducted in Canada. Results indicate a 7 percent higher risk for those who live within 50m (half a city block)compared to those who live more than 200 m from these roadways who have no higher risk. The specific pollutants found responsible include PM2.5 and NO2. Interesting that other neurological disorders such as Parkinson's disease or multiple sclerosis were found to not have a higher risk.

 dementia  

Key Quotes:

 “Dementia is more common in people who live within 50 metres of a major road than those who live further away.. up to one in 10 (7-11%) cases of dementia among those who live within 50 metres of a major road [1] could be attributed to traffic exposure”

“While there was no association between living near a road and Parkinson's disease or multiple sclerosis, dementia was more common the closer people lived to busy roads.”

 “The risk of developing dementia reduced as people lived further away from a main road - with a 7% higher risk in developing dementia among those living within 50 metres, a 4% higher risk at 50-100 metres, a 2% higher risk at 101-200 metres and no increase in risk in those living more than 200 metres away.”

"Our study suggests that busy roads could be a source of environmental stressors that could give rise to the onset of dementia. Increasing population growth and urbanisation has placed many people close to heavy traffic, and with widespread exposure to traffic and growing rates of dementia, even a modest effect from near-road exposure could pose a large public health burden. More research to understand this link is needed, particularly into the effects of different aspects of traffic, such as air pollutants and noise."

 "The significant association of newly diagnosed cases of dementia in the study period between 2001 and 2012 with the proximity to traffic road less than 50 m-300 m versus more than 300 m, and the robust observation of dementia involving predominantly urban versus rural residents, opens up a crucial global health concern for millions of people..”

“exposures to nitrogen dioxide (NO2) and fine particulate matter (PM2.5) on the basis of postal code addresses were related to dementia, and adjusting for these two pollutants attenuated its association with roadway proximity. This showed that the effect of living near a busy road may, at least in part, operate through this mechanism”

Tuesday, January 17, 2017

The Impact of Traffic-Related Air Pollution on Cloud Formation

Effect of vehicular traffic, remote sources and new particle formation on the activation properties of cloud condensation nuclei in the megacity of São Paulo, Brazil (22 page pdf, Carlos Eduardo Souto-Oliveira, Maria de Fátima Andrade, Prashant Kumar, Fábio Juliano da Silva Lopes, Marly Babinski, and Eduardo Landulfo, Atmos. Chem. Phys., Nov. 24, 2016)

 Today we review research on the impact vehicle emissions have on cloud formation in the largest city in South America with a 20M population and 7 M vehicles. Such a concentration of emissions may have global impacts on precipitation. Cloud condensation nuclei in this city originate from three sources: vehicle emissions, biomass burning in the vast tropical forests and from sea-salt. Careful direct and indirect (lidart) measurements over a four month period revealed that vehicles were predominant in producing these nuclei with two diurnal maxima during rush hours.

  trap-and-clouds  

Key Quotes:

“Atmospheric aerosol is the primary source of cloud condensation nuclei (CCN). The microphysics and chemical composition of aerosols can affect cloud development and the precipitation process.”

 “The high concentrations of CCN in the air favor the formation of clouds with small droplets, which can lead to suppression of precipitation in shallow and short-lived clouds”

 “Primary aerosols are emitted into the atmosphere directly by anthropogenic and natural sources. In contrast, secondary aerosols are formed in the atmosphere through the nucleation of no- or low-volatile gases containing inorganic and organic compounds, followed by growth to larger particles”

 “With over 20 million inhabitants, the MASP [Metropolitan Area of São Paulo] is the biggest megacity in South America. Therefore, the MASP represents an important city for global-scale atmospheric studies. The MASP fleet comprises more than 7 million vehicles, which constitute one of the main sources of particles, together with a variety of industries and construction activities “

 “The PNCs [particle number concentration]were highest between 07:00 and 19:00 LT, whereas they were lowest between 19:00 and 07:00 LT (Fig. 2b), hereafter referred to as the daytime and nighttime periods, respectively. During the daytime period, PNCs were elevated, especially during the rush hours, which are primarily associated with vehicular emissions. However, CCN peaks showed the opposite behavior, CCN concentrations being higher during the afternoon and the nighttime period. “

 “in the MASP, the morning rush occurs between 07:00 and 10:00 LT, whereas the afternoon rush occurs between 17:00 to 20:00 LT. The decrease began, and the lower values of AR [Mean activation ratio] occurred, during the morning rush and formation of a secondary aerosol. Vehicular traffic and secondary aerosol formation constitute the main sources of particles in megacities such as the MASP”

 “The regional atmosphere is highly affected by vehicular traffic emissions, and lower by remote sources such as biomass burning and sea-salt transport.”

“Our results show the influence that vehicular traffic, long-range transport of sea salt, biomass-burning plumes and NPF events have on CCN properties”