SLIDE 1 Exposure of Children to School Bus Exhaust
New Brunswick Lung Association New Brunswick Dept. of Education Health Canada Environment Canada
- Dr. David Brown EHHI, Dr Thelma Green RPC
SLIDE 2
CO2
PM1.0, PM2.5 CO, VOCs including polycyclic aromatic hydrocarbons benzene, 1,3-butadiene, toluene and xylene, aldehydes
Diesel emissions are a complex mixture of hazardous particles, gases and vapours
SLIDE 3
Symptoms most often associated with diesel exhaust exposure are: irritation of the eyes and nose broncho-constriction cough and signs of laboured breathing chest tightness and wheezing Diesel exhaust is a probable human carcinogen.
Health effects
SLIDE 4
Respiratory diseases are increasing in North America and are becoming one of the leading causes of death (Statistics Canada, 1997) Air pollution plays an important role in the development of several respiratory conditions: infections such as bronchitis and pneumonia exacerbation of chronic obstructive lung disease and asthma decreased lung function and lung growth lung cancer It also contributes to higher rates of heart attacks.
Population health
SLIDE 5 Studies have shown a causal relationship between traffic congestion, diesel exhaust and asthma (English et al., 1999; Ciccone et al., 1998, cited in Wargo et al., 2002). Asthma accounts for one quarter of school absenteeism and is the most common chronic disease plaguing children. In 2000/01, 8.7% of Canadians four years of age and over suffered from asthma. Between 1995 and 1999 the prevalence of asthma had increased by 14% among children between ages 4 and 11. It
- ccurs currently in approximately 7 to 10% of children
(Health Canada, 2002; Canadian Lung Association, 2004) In New Brunswick, in 2000/01, there were 8652 young people between the ages of 12 and 19 suffering from asthma.
Asthma and children
SLIDE 6
Objectives To determine the exposure of New Brunswick children to fuel exhaust-related pollutants on their daily way to school. To improve our understanding of the exposure of New Brunswick school children to diesel exhaust relative to the age of the bus and the length of the bus route. To offer policy recommendations based on the findings.
School Bus Study
SLIDE 7 Methods
Compounds measured were PM 1.0, PM 2.5, black carbon, and volatile organic compounds. A Dust Trak air monitor sampled continuous levels of particulate matter 2.5 g and smaller. A P-Trak sampled PM 1.0 g and smaller. An aethalometer measured levels of black carbon (BC) and UV- absorbing aromatic material. SUMMA cannisters were used to take “total-trip” samples of volatile
The research assistants recorded all relevant events in a log for each entire day. Data exists for 63 sampling days, over 75 bus rides and 11 walking routes.
SLIDE 8 Riding the bus exposes children to 3-5 times higher levels of PM2.5, and 2-3 times higher PM1.0 than does walking to school. Levels of VOCs were higher on buses but the variability could not be explained by age of bus or duration of route. Short bus rides have higher mean and maximum exposures to PM2.5. Long bus rides had higher cumulative exposures to PM2.5, PM1.0 and black carbon compared with short rides. The age, mileage, and type of fuel injection system (mechanical
- r electric) did not strongly affect exposures to PM2.5.
Colder temperatures tended to increase PM1.0 and higher humidity increased PM2.5. Higher ambient PM2.5 tended to increase PM2.5 inside buses.
Results
SLIDE 9 20 40 60 80 100 120 140 7:53:05 7:58:05 8:03:05 8:08:05 8:13:05 8:18:05 8:23:05 8:28:05 8:33:05 8:38:05 8:43:05 8:48:05 8:53:05 8:58:05 9:03:05 9:08:05 9:13:05 9:18:05 9:23:05 9:28:05 9:33:05 9:38:05 9:43:05 9:48:05 9:53:05 ug/m3 PM 2.5
20 40 60 80 100 120 140 12:52:33 13:01:33 13:10:33 13:19:33 13:28:33 13:37:33 13:46:33 13:55:33 14:04:33 14:13:33 14:22:33 14:31:33 14:40:33 14:49:33 ug/m3 PM 2.5
Walking Riding the bus
Examples PM2.5 exposure
20 40 60 80 100 120 140 6:58:33 7:07:33 7:16:33 7:25:33 7:34:33 7:43:33 7:52:33 8:01:33 8:10:33 8:19:33 8:28:33 8:37:33 8:46:33 8:55:33 ug/m3 PM2.5
SLIDE 10 5000 10000 15000 20000 25000 30000 35000 40000 45000
11:05:25 11:12:25 11:19:25 11:26:25 11:33:25 11:40:25 11:47:25 11:54:25 12:04:41 12:11:41 12:18:41 12:25:41 12:32:41 12:39:41 12:46:41
500 1000 1500 2000 2500
10:51 10:59 11:07 11:15 11:23 11:31 11:39 11:47 11:55 12:03 12:11 12:19 12:27 12:35 12:43 12:51
20 40 60 80 100 120 140 10:46:48 10:55:48 11:04:48 11:13:48 11:22:48 11:31:48 11:40:48 11:49:48 11:58:48 12:07:48 12:16:48 12:25:48 12:34:48 12:43:48 ug/m3 PM 2.5
Same bus ride: PM1.0, Black carbon, PM2.5
PM1.0 counts/m3 Black Carbon ng/m3 PM2.5 ug/m3
SLIDE 11
Eliminate bus idling Implement no-idling policy for all vehicles on school grounds Avoid caravanning Consider reducing the number of stops or relocating stops to areas with lower traffic density Locate exhaust pipes to upper left of rear of bus Air-filtering systems should be considered Retrofit diesel buses to achieve lower emissions New buses should have lowest emissions possible
Recommendations
