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Explora: Environment
and Resource Leaf burning air pollution

specific concentrations do vary) with other types of 3. Results
biomass burning such as wildfire, wood burning, and peat
wildfires. 2 3.1. Biomass burning of leaves, brush, forests, peat,
and wood produces somewhat similar mixtures of
The recent large increases in worldwide wildfires toxic pollutants
and the U.S. U.S. Environmental Protection Agency
decision dated February 07, 2024 to lower the annual Burning 907 kg of leaves will produce about 53 kg
PM limit from 12 µg/m to 9 µg/m air have focused of carbon monoxide, 29 kg of particulates with over
3
3
2.5
attention on biomass burning, the large amounts of PM half of them smaller than 2.5 µm in diameter, at least 7
2.5
they produce, and their many associated adverse health proven carcinogens (such as polyaromatic hydrocarbons
effects. 3-16 Many studies and reviews have reported that [PAHs] including benzo(a)pyrene) and many other toxic
2,18
chemicals. The burning of wood or wildfire, peat fires,
biomass burning produces large amounts of air pollution agricultural burning and tobacco/cannabis burning
and is associated with many adverse health effects also produce toxic mixtures containing PM , carbon
worldwide. 5,17 It has been estimated that air pollution monoxide, and may other toxic chemicals including
2.5
from biomass burning causes 130,000 excess infant carcinogens, which are somewhat similar to the pollutants
deaths annually worldwide. 17
released by leaf burning. 7,19-22 In general, lower-temperature
Several studies have reported that leaf/landscape biomass burning (such as burning leaves on the ground) is
burning is associated with significantly increased associated with higher rates of emissions of particulates,
outdoor levels of PM and other pollutants, significantly carbon monoxide, and hydrocarbons as compared to
2.5
increased rates of asthma and respiratory mortality, and higher-temperature burning (such as burning in barrels or
significant numbers of severe burn and smoke injury in a furnace). 23
to humans and buildings. In addition, many studies Direct comparisons of the air pollutants produced
have reported that wildfires produce high levels of air by leaf burning and other forms of biomass burning are
pollution, and are associated with significantly increased fairly scarce in the literature. One hindrance in comparing
rates of many health problems including respiratory, wildfire burning with leaf and other green waste burning
cardiovascular, and infectious morbidity and mortality. and with wood burning is that wildfire burning involves
Leaf and wildfire burning produce dark particles which burning mixtures of wood and leaves. A 2001 review
absorb sunlight and accelerate global warning by climate- reported that burning a 907 kg of mixed leaves produced
forcing mechanisms. an average of about 17.3 kg of particulates, 50.9 kg of

This review focuses on the dangers of leaf, brush, and carbon monoxide, 5.5 kg of methane, and 12.7 kg of non-
related burning. Some selected papers on wildfire burning methane organic compounds. Wildfire burning and
24
are reviewed since there have been large numbers of recent burning of 907 kg of forest residues was associated with
studies on air pollution from wildfires and their associated producing about 7.7 kg of particulates, 63.6 kg of carbon
adverse health effects. monoxide, 2.6 kg of methane, and 8.6 kg of non-methane
organic compounds. 24
2. Methods
According to Noblet et al., the burning of leaves,
2
This review attempts to report all relevant research relating green waste, brush, grassland, pastures, and stubble often
to the pollutants produced by and adverse health effects of produces significant quantities and often somewhat similar
the domestic burning of leaves, brush, and grass. Because profiles of carcinogenic polycyclic aromatic hydrocarbons
of the large amounts of recently published research across the different biomass burning types. They noted that
on wildfires, and the fact that many of the pollutants the total PAH production was about 1.8 times, which is great
produced by leaf/brush burning are roughly similar to that for hedge trimmings as compared to leaves (85.3 vs. 45.0 mg
produced in wildfires, selected papers on the pollutant of total PAHs produced per kilogram burned). Some
2
production and adverse health effects related to wildfires studies have reported that burning of wood in unmodified
are reviewed. Databases and search engines, including in fireplaces is associated with 3 – 12 times higher production
PubMed, EMBASE, and Google Scholar, were searched for of benzo(a)pyrene-equivalent polyromantic hydrocarbons
the relevant English language papers. Keywords searched as compared to wood burning in low-emission fireplaces,
included words such as “leaf burning,” “brush burning,” burning of leaf, grass, and savanna, as well as wildfire
“wood burning,” “wildfires,” “brush burning,” “peat fires,” burning of biomass. Noblet et al. also reported somewhat
2
2
“grass fires,” “biomass burning,” and many words relating similar emission profiles of monosaccharides, simple
to adverse health effects. Efforts were made to ensure a sugars, alkanes, and methoxyphenols between leaf and
balanced view of the literature. brush burning. The production of odd-carbon-numbered

Volume 1 Issue 1 (2024) 2 doi: 10.36922/eer.4040