Wednesday, May 30, 2012

Heart Disease in Polluted Urban Cores

Sternocostal surface of heart. (Right coronary...
Sternocostal surface of heart. (Right coronary artery visible at left.) (Photo credit: Wikipedia)
 The relation between coronary artery calcification in asymptomatic subjects and both traditional risk factors and living in the city centre: a DanRisk substudy (Abstract, J. Lambrechtsen, O. Gerke, K. Egstrup, N. P. Sand, B. L. Nørgaard, H. Petersen, H. Mickley, A. C. P. Diederichsen, Journal of Internal Medicine, Dec. 20,2011) 

 Today we review research that looked at the heart disease impacts for those living in city centres. Results indicate a much greater chance of heart disease there than in the suburbs or rural areas, especially with men. 

Key Quotes: 

"Our study aimed to evaluate the association between living in a city centre, which is often used by researchers to indicate exposure to air pollution, and the presence of coronary artery calcification in men and women showing no other symptoms of heart disease" 

“The study also found that people who lived in city centres were 80% more likely to develop CAC [coronary artery calcification] than those living in other areas” “rates were approximately three times higher in city centres than other urban areas and seven times higher than in rural areas.” 

“Men were more than three times as likely as women to develop CAC, with a 220% higher odds risk.” 

 "The place where a person lives is often used as a surrogate for exposure to air pollution in research. In this study we found that, even after adjusting for demographic and clinical variables, where people lived was independently associated with CAC and that CAC levels were highest in people living in city centres”
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Monday, May 28, 2012

Active Transportation Choices and Health in Toronto

Road to Health: Improving Walking and Cycling in Toronto (109 page pdf, Toronto Public Health, April 2012)

Today, we look at a report on Toronto that examines how walking and cycling as active transportation modes benefit health and how much more improvement could be achieved if both forms were optimized. Estimated benefits are over 129 fewer deaths/year and $475 M/year which could be doubled by choosing active transportation modes to only match the active transportation statistics in Vancouver which has both fewer collisions and deaths and higher modal statistics than Toronto. Many options could be pursued from the range of best practices presented, such as Traffic Demand Management to reduce traffic speed and
 collisions that make walking and cycling a safer choice.


Key Quotes:

“this report synthesizes evidence on health benefits and risks associated with walking, cycling and physical activity related to the use of public transit, as well as economic assessments and specific strategies to increase the use and safety of active transportation in Toronto.”

“About 55% of all trips in Toronto are less than 7 km, and are therefore very conducive to cycling. Over 20% of all trips are under 2 km and therefore very walkable.. cycling is almost as fast as driving for trips of 7 km in urban areas, and walking is generally as fast as driving for trips of 500 m and less”

 “30% of collisions happen mid-block (primarily related to collisions with car doors) and may be linked to inadequate separation of cyclists from motor vehicles… Elderly pedestrians are most likely to be killed in collisions with vehicles; children and residents of low-income neighbourhoods may also be particularly at risk of injury when walking and cycling”

 “Current levels of active transportation are estimated to prevent about 120 deaths per year in the Toronto population. This mortality reduction alone can be associated with over $475 million in economic benefits.. By achieving Vancouver and Portland’s walking and cycling commuting mode shares (12% and 6%, respectively), Toronto could prevent an estimated 100 additional deaths each year”

 “At least 21% of all trips could be made using walking, and 55% of all trips in Toronto could be made by cycling. Toronto’s median commute distance of 7.5 km further indicates that half of all trips to work could be made using active transportation”

 “47% of collisions between pedestrians and motor-vehicles could be prevented through improved safety at intersections in Toronto. 37% of collisions between cyclists and motor vehicles could be prevented through improved safety at intersections… New York City plans to redesign almost 100 km of streets for greater pedestrian safety as part of their goal of reducing fatalities by 50% ”
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Friday, May 25, 2012

What Makes a Walkable City?- a look at Canada’s largest city

The Walkable City: Neighbourhood Design and Preferences, Travel Choices and Health (58 page pdf, Toronto Public Health, April 2012)

Today we look at Toronto and the Greater Toronto Area (GTA) which has many of the challenges faced by other large American and Canadian cities which have evolved to a car-oriented end state that discourage walking and cycling – modes where Toronto lags behind Montreal and Ottawa. The results of a survey are encouraging- most residents prefer more walkable neighbourhoods and those who have them enjoy less pollution and healthier environments.  

Key Quotes: “there are specific neighbourhood features, such as having shops and services within walking distance of homes, and having a variety of small and medium sized food stores within walking distance of homes, that are strongly desired by Toronto residents.” “These results suggest:
  • that people living in more walkable neighbourhoods in the GTA are more physically active with less chance of developing a chronic disease, than those who live in less walkable neighbourhoods
  • that there may be significant air quality, climate change, and traffic reduction benefits associated with walkable and transit-supportive neighbourhoods.”
“three quarters of Toronto residents surveyed expressed a strong preference for the walkable neighbourhood, while only 6% expressed a strong preference for an auto-oriented neighbourhood ”

 “a number of the neighbourhoods in Toronto that are least walkable are home to low income residents who can experience increased rates of illness and injury. This is important because walkable neighbourhoods provide so many health and social benefits”

“Old neighbourhoods, such as the West Don Lands, can be transformed from an industrial area into pedestrian-friendly and transit-supportive neighbourhoods. Apartment-oriented neighbourhoods can be revitalized with the introduction of shops and services that meet the needs of nearby residents.”
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Wednesday, May 23, 2012

Geo-Engineering Cities Using White Roofs and Pavements

The long-term effect of increasing the albedo of urban areas (11 page pdf, Hashem Akbari, H Damon Matthews, Donny Seto, Environmental Research Letters, Apr. 12, 2012)

Also discussed here: Resurfacing Urban Areas to Offset 150 Billion Tons of CO2 (ScienceDaily, Apr. 13, 2012)

Today, we review a look at changing the albedo of urban areas of the world and then estimating how much this would reduce climate warming in terms of offset CO2. The key “dark”, and therefore highly absorbing, surfaces of most cities are the black roofs and pavements which make up 60% of the area and are normally replaced every decade or two. By increasing the albedo of urban areas in a global climate model and running a simulation for 80 years ahead, the authors estimated a CO2 offset of between 130 and 150 billion tones- equivalent to taking every car in the world off the road. These reductions could be put into effect by changes at the municipal level with benefits in terms of reduced urban heat islands and urban smog.  
Key Quotes:

 “increasing the albedo of the urban areas and human settlements (hence increasing the albedo of Earth as a whole) by increasing the reflectivity of artificial urban surfaces (rooftops, pavements), is based on proven technologies that have been used for centuries with no known negative effect”

 “Pavements and roofs comprise over 60% of urban surfaces (25% roof and 35% pavement)”

“We used the University of Victoria Earth System Climate Model (UVic ESCM), an intermediate complexity global climate model which includes an interactive global carbon cycle.. as a spatially explicit model with reduced atmospheric variability, this model is well suited to assess the climate response the small and spatially variable forcing associated with urban surface albedo modification”

 “increasing the reflectance -- commonly known as albedo -- of every urban area by 0.1 will give a CO2 offset between 130 and 150 billion tonnes. This is equivalent to taking every car in the world off the road for 50 years CO2”

 "Typically roofs are resurfaced (or changed) about every 20-30 years; paved surfaces are resurfaced about every ten years. When roofs or paved surfaces are installed, they can be changed to materials with high solar reflectance, typically at no incremental cost,"

 “Cool roofs save air conditioning energy and reduce CO2 emissions. Cool roofs and cool pavements (Cool Cities) reduce the urban heat island, improve comfort, and reduce urban smog”

 “We propose customizing local ordinances, standards, policies and programs to promote the use of white or light color urban surface materials as they are replaced”
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Monday, May 21, 2012

Do More Roads Have Less Traffic?

Vehicle miles travelled on US roads 
Vehicle miles travelled on US roads (Photo credit: Wikipedia) 

Edward Glaeser’s Triumph of the City (Grush Hour, Apr. 11, 2012) 

Today, we review a book by Edward Glaeser (with a nod of appreciation to Bern Grush’s blog) on cities and some highly quotable quotes about the need to price peak demand for road use in order to make roads more usable for all and cities more friendly for their citizens.  

Key Quotes: 

“Too much trash turns city streets into a health hazard; too many drivers turn city streets into a parking lot” 

“For decades, we’ve tried to solve the problem of too many cars on too few lanes by building more roads, but each new highway or bridge then attracts more traffic…vehicle miles traveled increases essentially one-to-one with the number of miles of new highway” 

“When we drive, we consider the private costs to ourselves of the time, gas, and automobile depreciation, but we don’t usually consider the costs—the lost time—we impose on every other driver. We don’t consider the congestion we create” 

“the gap between what is known about congestion management among transport economists, urbanologists and traffic managers vs what is understood and accepted by politicians, journalists and drivers keeps a solution at bay”
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Friday, May 18, 2012

Lifetime Population Exposure to Air Pollution in Canada

Spatiotemporal air pollution exposure assessment for a Canadian population-based lung cancer case-control study (26 page pdf, Perry Hystad, Paul A Demers, Kenneth C Johnson, Jeff Brook, Aaron van Donkelaar, Lok Lamsal, Randall Martin and Michael Brauer, Environmental Health, Apr.4, 2012)

 Today, we review a report that develops a method of assessing exposure to air pollution over several decades, based on the exposure of residents to air pollution from industrial and mobile sources, as deduced from the conventional national air pollution network and from vehicle emissions, updated using space based sensors on the OMI satellite. The approach used will likely be very useful for then assessing the lifetime risk of cancer from accumulated exposure to air pollution.  
Key Quotes:

“The spatiotemporal exposure assessment included three steps:
  • national spatial surfaces were created from recent satellite-based estimates (for PM2.5 and NO2) and a chemical transport model (for O3)…
  • National Air Pollution Surveillance (NAPS) monitoring data were compiled and formatted for the study period, including 120 NO2 stations and 1030 measurement-years…
  • spatial pollutant surfaces were calibrated yearly to estimate average annual concentrations between 1975 and 1994”
“Exposures to vehicle emissions were estimated using proximity measures to highways (freeways and major highways) and major roads (freeways, highways, and arterial and collector roads).. within 50, 100 and 300 m.. living near a major road in 1975 is equivalent to 1.26 “1994” years due to changes in vehicle emissions (the ratio also accounts for changes in vehicle numbers)”

 “only 40% of participants lived at their study entry residence for the entire 20 year exposure period”

 “The exposure assessment methods developed here will allow subsequent epidemiological analyses to examine latency periods associated with lung cancer, include both urban and rural populations, and study the contributions of multiple ambient pollutants and local vehicle and industrial emissions to lung cancer risk in Canada”
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Wednesday, May 16, 2012

Citizen-Led Air Quality Sensor Networks

The Air Quality Egg Project (An Open Hardware project in New York, NY by @EdBorden)

 Also discussed here: Air Quality Egg (Wiki) And here: You can help build an open air quality sensor network (Pachube, Dec. 7, 2011)

 And here: MIMAQ (15 slides, mobile pollution sensors)

And here: Air Quality Monitoring: A Few Precedents (12 page pdf, NYC Open Sensor Network Workshop, Dec. 2, 2011)

The focus today is on a developing citizen-led air quality network in New York City and in other cities worldwide. The Air Quality Egg Project makes use of low cost technology and many volunteers to produce high resolution maps of the urban air environment which provides much more detail than conventional regional networks operated by the government.

Key Quotes:  

The Air Quality Egg is a sensor system designed to allow anyone to collect very high resolution readings of NO2 and CO concentrations outside of their home”

“The basic unit comes in two parts: a “base station” RF platform that would plug directly into the ethernet port of a wi-fi router, and an enclosed sensor node that communicates wirelessly within 40-50 yards…Applications will be limited and basic at the outset as the design of the network has the enablement of third-party applications at its core…. This group's sensor systems will be the start, but the network will be open to adding hardware (eggs) designed by others onto the core base station.”

“The air quality data collected by the government is likely sampled from far, far away and then applied to you on a regional level, almost completely useless from the standpoint of trying to understand or change the local dynamics of pollution that affect you.”

 “ultrasensitive sensors that have very localized measurements may actually be a problem as they provide too localized information to be useful (peak when a scooter passes by)”

 “sensors behave differently though measuring the same pollutant - even if they are from the same production unit. It is not even clear what they measure exactly, in some cases (due to correlated pollutants amongst others). One solution would be sensor arrays (of different sensors measuring the same thing)”

 “combine low-cost + more sophisticated sensors, air quality models and contextual information”
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Monday, May 14, 2012

Safe Roads for Seniors

Keeping Baby Boomers Mobile: Preserving the Mobility and Safety of Older Americans (25 page pdf, TRIP and American Association of State Highway and Transportation Officials, Feb. 2012)

Also discussed here: Forgive and Forget (Streetsblog, Mar. 5, 2012)

 And here: Few U.S. cities are ready for aging Baby Boomer population (USA Today-Your Life, Mar. 25, 2012)

 Under review today is a report that looks at the safety issues on local streets that the growing older population either drives on (80% of them do) or uses on foot. These include: the higher risks for seniors making left turns at intersections and the window available for them to avoid heavy traffic, becoming shorter because of the increased congestion from noon on. Combining these issues with the poor design of many city streets that borrow from highway design and fail to achieve either mobility or efficiency- the “STROAD”. The future will see twice as many seniors so that all these problems will amplify in the absence of corrections.  

Key Quotes:

 “This aging population will both create and face significant transportation challenges, including a transportation system that lacks many features that would accommodate the level of mobility and safety older Americans desire and expect.. Projections show that one in every five drivers will be 65 or older by 2025”

 “Older Americans tend to “age in place”, remaining in the homes where they raised their children and held jobs. Seventy-nine percent of elderly Americans live in suburban (56 percent) or rural (23 percent) communities”

 “Older drivers make a greater proportion of shopping trips, more family and personal errands, and more trips for social and recreational activities than younger adults…Travel by older drivers now accounts for eight percent of all miles traveled in the U.S..90 percent of travel takes place in a private vehicle.. public transit accounts for just 1.3 percent of trips by older Americans”

 “Older drivers are disproportionately affected by mounting levels of congestion..their window of opportunity for travel narrows considerably as morning and evening rush hours become longer and midday congestion continues to grow”

 “37 percent of all fatal crashes where at least one driver was aged 65 or older occurred at an intersection or were related to an intersection.. each advancing year of age after 65 increases by eight percent the odds of getting into a crash that involves turning left”

 “A STROAD is a street/road hybrid..functions neither as a road that moves people quickly between two places nor as a street that provides a platform for capturing value… is created when we misapply to local transportation corridors the decades of wisdom we have gained from experimentation on highway design and construction techniques”

 "There are a lot of communities that recognize they need to do something but haven't done it yet..Some of the changes cities can make include offering training to help older people drive more safely, installing road signs that are easier to read or creating ride-share programs”
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Friday, May 11, 2012

The Challenge of the Future for the Cities of the World

Planet Under Pressure - A major international conference focusing on solutions to the global sustainability challenge (Mar. 26-29, 2012, London, UK)

Also discussed here: Sustainable Cities: Meeting the Challenge of Rapid Urbanization the Focus of “Planet Under Pressure 2012″ (Andrew Burger, Triple Pundit, Mar. 28, 2012)

And here: Planet under pressure / Navigating the Anthropocene (Susan MacMillan , ILRI news, Mar. 29, 2012)

 And here: Human activities and global environmental change (28 slide PowerPoint show, Diana Liverman, 2012)

The focus today is on a major conference held in London at the end of March 2012 where the topic was the impact humanity is increasingly having on the world’s environment, a process now referred to, in geological terms, as “the Anthropocene”. Urbanization world-wide is expected to grow over the next 20 years to an area greater than Germany, Spain and France combined. How prepared is society for these changes?

 Key Quotes:

“With world population forecast to increase from 7 billion today to more than 9 billion by 2050, humanity’s urban footprint will take up 1.5 million more square kilometers of land by 2030 at current rates.. That translates into an average 1 million more city dwellers every week for the next 38 years”

 “Dense cities designed for efficiency offer one of the most promising paths to sustainability”

“Cities are responsible for more than 70% of global CO2 emissions.. estimated at about 15 billion metric tons in 1990.. growing to 36.5 billion by 2030”

“Focusing on “urban efficiencies,” such as using weather conditions and time of day-adjusted tolls stems to reduce traffic congestion, is essential if the world’s societies are to address climate change”

 “smart buildings, cars, transportation, power, water and waste systems are examples of an emerging “Internet of things..offering a fast-growing number of high-tech, artificially intelligent, Internet-connected cars, appliances, cameras, roadways, pipelines and more”

“‘Within one lifetime, humanity has become the prime driver of change on the planet. We are pushing Earth towards thresholds in the Earth system; we have many solutions but lack the urgency to implement them. We must set the scientific agenda, she says, to set the world on the path of ‘transforming our way of living’ ..and ‘fundamental reform needed to create a genuinely sustainable society”
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Wednesday, May 9, 2012

Harvard Six Cities Study Update on Mortality from Exposure to Fine Particles

Chronic Exposure to Fine Particles and Mortality: An Extended Follow-Up of the Harvard Six Cities Study from 1974 to 2009 (31 page pdf, Johanna Lepeule, Francine Laden, Douglas Dockery, Joel Schwartz, Environ Health Perspect, Mar. 28, 2012)

 The research article of interest today is an update of the famous 1993 Six Cities Study (in the USA) that established links between long term exposure to fine PM and mortality. The newer research continued to showed a significant relationship between PM 2.5 and both lung and cardiovacular mortality, without any lower safe threshold and points to the public health benefits of further reductions in PM 2.5 levels.  
Key Quotes:

“Our goal was to test the robustness of the association between chronic exposure to PM2.5 and mortality observed in the original study (Dockery et al. 1993)… replicating the analyses using eleven additional years of follow-up with exposures well below the US annual standard (15μg/m3)”

 “Including more recent observations with PM2.5 exposures down to 8μg/m3, we continued to find a statistically significant association between chronic exposure to PM2.5 and all-cause and cardiovascular mortality”

“Our results indicated a statistically significant 14% increase in all-cause mortality for a 10μg/m3 annual increase in PM2.5” “the present extended follow-up estimated a statistically significant 37% increase in lung cancer mortality (for each 10μg/m3 increase in PM2.5)”

 “Given that there were 2,423,712 deaths in the US in 2007..and that the average PM2.5 level was 11.9μg/m3 (EPA), our estimated association between PM2.5 and all-cause mortality implies that a decrease by 1μg/m3 in population average PM2.5 would result in 33,932 fewer deaths per year”

 “the relationship between chronic exposure to PM2.5 and all cause, cardiovascular and lung cancer mortality was found to be linear without a threshold.. further public policy efforts that reduce fine particulate matter air pollution are likely to have continuing public health benefits
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Monday, May 7, 2012

Diesel Trucks, Oil-Heated Homes and Childhood Asthma

 Domestic airborne black carbon and exhaled nitric oxide in children in NYC (Abstract, Alexandra G Cornell, Steven N Chillrud, Robert B Mellins, Luis M Acosta, Rachel L Miller, James W Quinn, Beizhan Yan, Adnan Divjan, Omar E Olmedo, Sara Lopez-Pintado, Patrick L Kinney, Frederica P Perera, Judith S Jacobson, Inge F Goldstein, Andrew G Rundle, Matthew S Perzanowski, Journal of Exposure Science and Environmental Epidemiology, Feb. 29, 2012)

Also discussed here:
Air Pollution from Trucks and Low-Quality Heating Oil May Explain Childhood Asthma Hot Spots (Science News, Mar. 27, 2012)

Today’s review deals with the health of children in New York City who live near diesel truck traffic. Results show up to three times greater risk for asthma and the need for further reductions in emissions from buildings burning low grade heating oil and from diesel trucks whose routes take them near homes.

Key Quotes:

 “Neighborhood built-environment characteristics were assessed for the 500 m surrounding participants’ homes. Airborne BC concentrations in homes correlated with neighborhood asthma prevalence.. and neighborhood densities of truck routes ..and buildings burning residual oil”

“In New York City… asthma among school-age children ranges from a low of 3% to a high of 19% depending on the neighborhood, and even children growing up within walking distance of each other can have 2- to 3-fold differences in risk for asthma”

“levels of airborne black carbon, which mostly comes from incomplete combustion sources like diesel trucks and oil furnaces, were high in homes of children with asthma”

"Because of its history as a shipping and oil refining center, New York City burns more dirty oil for residential and commercial heating than any other city in the country,"

"Children in this study with higher black carbon in the air of their homes had higher exhaled nitric oxide, suggesting that they were at greater risk for asthma exacerbations”

Friday, May 4, 2012

Intelligent Parking Rates and Pricing

The Future of Intelligent Parking (Nate Berg, The Atlantic Cities, Mar. 23, 2012) Also discussed here: San Francisco Pilot Parking Program Watched By Other Cities (Irwin Dawid, Planetizen, Mar.21, 2012)

Today we review another article on the expanded use of smart parking meters and parking systems which began in San Francisco and now is being tested with pilots in a number of American cities: Boston, Fort Worth, New York, Los Angeles, Washington, D.C, and Indianapolis.  

Key Quotes:

  “wirelessly connected networks of sensors and computer systems that accurately track the availability of parking spaces and enable variable pricing that changes with demand”

“The goal of intelligent parking systems:
  • to know where parking is available and to let the driver know as well, making it easier for cars to find their way into parking spots.
  • to understand just where parking is in demand and when. For cities, this information can be extremely useful..Parking is generally the second or third largest source of revenue for a city”
“San Francisco recently became the first major city to act…On-street parking spaces and city-owned garages are equipped with meters so the city can track occupancy rates and adjust pricing throughout the day”

 “ExpressPark [in Los Angeles] will be linked up with the mobile phone drivers to nearby parking options, with details about pricing, availability of spaces and even deals offered by parking facilities. The app also allows users to re-up their meters or set timers"
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Wednesday, May 2, 2012

Characteristics and Components of Particulate Matter

Characterization of Fine Particulate Matter and Associations between Particulate Chemical Constituents and Mortality in Seoul, Korea (34 page pdf, Ji-Young Son, Jong-Tae Lee, Ki-Hyun Kim, Kweon Jung, Michelle L. Bell, Environ Health Perspect , Mar.22, 2012)

Today we review some leading edge research into the make-up of particulate pollution from the aspect of what associated chemicals are found with PM 2.5 and how do they affect their impact on human health. Results indicate higher concentrations of PM 2.5 in winter than summer when rain cleans the atmosphere and higher in late morning and evening because of vehicle emissions. Magnesium (Mg) was found to increase mortality rates at least in South Korea where the data were gathered.  
Key Quotes:

 “The chemical characteristics of Seoul’s PM2.5 were more similar to Western U.S. PM2.5 than the Eastern U.S. PM2.5 with lower SO4 contributions and higher NO3 contributions, although overall PM2.5 levels were much higher”

 “Several components that were among the largest contributors to PM2.5 total mass (NO3, SO4, and NH4) were moderately associated with same-day cardiovascular mortality at the p<0.10 level”

 “observed significant positive associations between several components (e.g., Mg, NH4, and NO3) and cause-specific mortality in Seoul, Korea”

“The higher PM2.5 concentrations in winter are likely due to increased emissions (from combustion sources for heating) and a lower mixing height The lower concentrations of PM2.5 in summer may relate to the large amounts of wet deposition as a function of precipitation, which is the major process of particle removal from the atmosphere, with 49% of the year’s deposition in this season”

“PM2.5 mass and some components (e.g., OC, EC, NO3, and NH4) showed similar patterns of daily concentrations, with peaks in late morning and evening. The peak started to form in the early morning or evening, attributed to the heavy traffic and increased several hours later”

 “We found significant positive association between Mg and total mortality… Likewise, secondary products of fuel combustion (NO3, SO4, and NH4) exhibited the stronger associations with cardiovascular mortality than did other components”
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