# Activity 7.1 [[Question]] What are the main local sources of outdoor air pollution in your area? When are people likely to come into contact with high levels of air pollution? In Jakarta, the main sources are from coal plants near Jakarta. Jakarta has 8 coal plants in the range of 100km from the city, and 4 new plants were planned to start running. It has been heavily criticized and became a main contested idea during the last Presidential debate. Coal plants produced sulfur oxide, nitrogen oxides, and particulate matters that are proven to harm our health. The next one is transport. Jakarta is one of Indonesia's metropolitan cities where central government and business centres operate. People surrounding Jakarta came to Jakarta to work. On one occassion, the population living in Jakarta was estimated to be 8 million people, but during the workhours, +4 million people came to Jakarta to work. The third source is forest fire. # Activity 7.2 [[Question]] How might you use epidemiological evidence to estimate the burden of premature mortality (numbers of excess deaths) due to exposure to particles from anthropogenic sources in your country? Health impact assessment need several pieces of information: 1) What is the population exposures to PM2.5 from anthropogenic sources? Use population-weighted average of PM2.5 for every 1km2, then multiplying it by the proportion of the total population who live in that square kilometer. For the UK, it was estimated to be 10.4 mikrogram/m3. However, only 86% of that PM2.5 is from anthropogenic sources - the remainder is of natural origin. So, we assume the population exposure to anthropogenic PM2.5 is: 0.86 * 10.4 = 8.9 mikrogram/m3. 2) How can we relate this to health? Calculate the RR of PM2.5. We will arrive at RR 1.05, which means 5% additional deaths will be attributed to air pollution of PM2.5. 3) How do we estimate the attributable burden? If the rough estimate of the total number of deaths in the UK per year is 600,000 then we can estimate that additional 0.05 point would have been brought forward in time because of exposure to anthropogenic pollution if they had experienced the 2008 concentrations over a long period. 4) What should you keep in mind? The relationship between PM2.5 and death is casual, the relationship between exposure and risk of death (strictly log risk) is linear - we assumed that the relationship was a straight line, but the exposure-response curve could take a non-linear shape. The calculation does not tell us how much earlier deaths are occurring because of air pollution exposure. # Policy approaches to outdoor air pollution > Setting ambient air quality standards, emission standards, technological controls and those implemented through market-based and voluntary approaches. Market-based approaches to air pollution are increasingly used alongside other control policies. An example of a market-based approach is emissions trading programmes, in which a cap on the total amount of emissions of a specific pollutant is set and emitters trade permits in an open market. Emissions trading is most commonly discussed for carbon, but also other pollutants such as NOx. This approach aims to make lower emissions financially advantageous, although critics raise concerns about how the emissions threshold is determined (what level is acceptable and whether the required data are available), the procedure for allocating the permits (e.g. if permits are freely allocated or auctioned), and also question the ability of governments to enforce the trading schemes. An additional approach to protect public health is to implement [[air pollution alert systems]] that warn susceptible individuals on high air pollution days so that they may modify their behaviour (e.g. stay indoors, delay physical activity) on that day to reduce their personal exposure. # Road transport and health Worldwide energy use from transport sector has risen steadily 2-2.5% per year since the early 1970s. The largest growth in in road transport has been in LMICs, where there has been larger population and economic grwoth compared to HICs. ## Traffic-related air pollution The evidence that specifically traffic-related air pollution causes exacerbation of symptoms among asthmatic children is strong (HEI 2009). The evidence for causation is less strong for mortality, cardiovasuclar morbidity, asthma incidence in children and respiratory symptoms in adults, while it is insufficient regarding the relationship with other health outcomes including adverse birth outcomes and cancer (HEI 2009). In the absence of sufficient evidence for pollution from traffic alone, estimates of the impact of traffic pollution on health use the relative risks derived from studies of total air pollution. ## Activity 7.3 [[Question]] Liquid biofuels are currently one of the few alternatives to fossil fuels for use in motor vehicle transport. They produce fewer PM10 compared to fossil fuels. However, this finding does not necessarily equate to reduced air pollution-related health burdens. What other factors do you think should be considered when assessing the impacts on air quality and hence on health of a change in a vehicle fuel? 1. The size. Measuring health effect are more concentrated on PM2.5 (fine particles) rather than PM10. Reduced PM10 does not always mean reduced PM2.5, although the two are usually strongly correlated. 2. The composition. PM is a heterogenous mix of particles. Some components may be more toxic than the others, and the composition of PM from liquid biofuels must be assessed first whether the they are more toxic or no. 3. Other pollutants. PM is not the only pollutant of concern with regard to public health. Other pollutants such as ozone are also associated with negative health effects. Combustion of liquid biofuels releases ozone precursors and may increase the formation of ground-level ozone (Jacobson 2007). Different transport fuels may therefore reduce emissions of some health-relevant air pollutants, but increase others. 4. Emissions at other stages in the biofuel life-cycle. Although liquid biofuels often show reduced exhaust emissions, emissions during production and distribution can be high. ## Road traffic injuries Road traffic accidents are the leading cause of death among young people (aged 15–29) and the burden is particularly high in LMICs where over 90 per cent of global traffic fatalities occur. Within high-income countries, people living in lower socioeconomic conditions are more likely to be involved in road traffic accidents compared to others who are better off (WHO 2012). [[Question]] The harm from road transport can be viewed as the product of what? (three) (1) potentially risky conditions, (2) the probability of a crash in those conditions, and (3) the consequence of the crash (e.g. fatality, injury) (Sivak and Tsimhoni 2008). Measures to promote road safety can target any of these three dimensions. Several features in road design aim to reduce harm primarily for vehicle occupants, but may also benefit other vulnerable road users like pedestrians and cyclists. Seatbelts have been an important safety measure in reducing the consequences for occupants in the event of a crash; seatbelts are estimated to reduce the risk of serious and fatal injuries by 40 and 65 per cent repectively (Ameratunga et al. 2006). ## Physical inactivity Widespread motorization has important implications for physical activity by replacing active forms of transportation such as walking and cycling with sedentary forms. Increased reliance on motorized transport over the past decades in high-income countries is likely to have played a role in increasing rates of physical inactivity. [[Active commuting]] There is good evidence that commuter walking and cycling are beneficial for reducing all-cause mortality (Hallal et al. 2012). Active commuting among children has been associated with reduced body-mass index and reduced cardiovascular risk factors (Hallal et al. 2012). The benefits of physical activity and how this can be facilitated by appropriate urban planning are discussed in Chapter 9. These benefits should be considered against the risks of injury from road traffic accidents and increased exposure to air pollution from individuals participating in walking and cycling. The relative trade-offs in terms of health risks are likely to depend on local contexts. ## [[noise pollution|Noise]] Excessive noise, or unwanted sound, is harmful for health and interferes with people’s daily activities at home, work and school. In many urban areas, road transport is a major source of environmental noise as well as air pollution. Noise from road transport depends on the distance from source, traffic volumes and vehicle mix as well as the surrounding topography (e.g. building heights) of an area. Environmental noise has been associated with cardiovascular disease (Selander et al. 2009; Gan et al. 2012); cognitive impairment in children (WHO Europe 2011); disruption of sleep and annoyance (Pirrera et al. 2010). Noise from road transport may be tackled by reducing the amount of noise produced per vehicle, reducing the number or speed of vehicles in an area, constructing sound barriers, or siting of major roadways away from residences and workplaces. ## Activity 7.4 [[Question]]Imagine a scenario in a city where there are three changes, and what are the implications of each scenario (Which health outcomes would you consider? Which impacts on health would you expect to be the largest?): 1. Business as usual: projection of existing trends in population and increasing car use, with some increase in rail use 2. Low emission motor vehicles: mandatory lower emission motor vehicles and use of alternative fuels 3. Increased active travel: reversal of present trends in car use and reductions in motorcycle use; large increases in walking, cycling, and rail use. The health outcomes I would consider directly links to the health effects of pollutants coming from increasing use, such as NO, CO, and PM2.5. For example: 1) reduced physical activity impact on cardiovascular diseases, stroke, diabetes, and cancer. 2) Prolonged, increased exposure from PM2.5 impact on respiratory diseases and lung cancer in adults and acute respiratory infections in children, and 3) motor vehicle traffic on the number of pedestrians and cyclists injured in road accidents. ### Scenario 1 Business as usual will not improve or gain any years of life, neither from physical activity, air pollution, nor from avoided road traffic crashes. ### Scenario 2 With low emission motor vehicles, at best we will gain years of life from reduced exposure to air pollution. ### Scenario 3 The best scenario, where we will gain years of life from those three components. # Summary This chapter has provided broad overviews of the related, but distinct, topics of outdoor air pollution and road transport in relation to human health. Several outdoor air pollutants are relevant for human health and these are generated from a range of sources. Time-series and cohort studies are the primary epidemiological study designs that have given rise to the now large body of evidence regarding the health effects of outdoor air pollution. [[Question]] What are the strategies available to reduce outdoor air pollution? Implementing air quality and emission standards, emission trading schemes, and encouraging the use of cleaner technologies. Road transport is not only an important source of human exposure to air pollution but also presents a risk of injury and has implications for health through reduced physical activity.