Course:SPPH381B/TermProject/Charcoal - Zahra

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Project Overview

The objective of this project was to select an everyday object and consider how different people – “workers” – are involved in the object's lifecycle, and how the production of that object has potential to adversely influence the lives of those workers. The manufacturing, distribution, and disposal processes, among others, were considered. Along several steps of the object’s “life-cycle”, one or more processes were chosen to be described in detail and underwent a risk assessment. From each risk assessment, one hazard was chosen to be measured, evaluated and strategies for its mitigation or elimination were discussed.

Introduction

The item chosen for this project was charcoal, which can be defined as the solid residue remaining when wood is “carbonized” or “pyrolysed” under controlled conditions in a closed space such as a charcoal kiln [1]. Although other materials such as nutshells, bark, and agricultural residues can be all used to produced charcoal, wood is the preferred and most widely available material for charcoal production [1]. In many low-income countries, charcoal production is an informal sector and provides income for a large number of subsistence farmers [2] [3]. Charcoal production can pose significant ecological and health challenges [3]. Most of the literature has thus far focused on the environmental effects of charcoal production. This project analyzes the occupational health hazards associated with the industry.

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Informal production involves small-scale producers using traditional technologies [4]. Natural forests are the primary source for harvesting wood to make charcoal. However, oten times the wood is harvested illegally [4]. It is estimated that approximately 52 million tons of wood charcoal were produced in 2015 of which Africa produced 62% [5]. Brazil is currently the largest charcoal producer globally and is the country of focus for this project.

Figure 1.2 Global Charcoal Production Region Proportions 2015 FAOSTAT

Charcoal Production by Region.png


Figure 1.3 Top 10 Charcoal Producing Countries 2015 FAOSTAT

Top 10 Countries Charcoal Production 2015 FAOSTAT.png

Charcoal in Brazil is used residentially, as well as for industrial processes and the production of pig iron [6]. It provides the high-carbon fuel to smelt iron core into pig iron, which is then developed into steel [7]. Residential use for charcoal is estimated at 8.3% of total use of which 1.3% or 2.4 million people use it directly for cooking [6]. Both native forests and forestry plantations are sourced for wood to make charcoal [6]. Charcoal production in Brazil is dominated by traditional methods heavily dependent on human labor. These methods are poorly mechanized and workers are often subject to precarious conditions such as being under temporary contracts, not having any social protection, long work hours, inadequate pay and hazardous work environments [6] [8].

Lifecycle

Charcoal-making can be divided into the following steps:

  • wood harvesting
  • drying and preparing the wood for carbonization
  • carbonizing the wood to charcoal
  • screening, storage and transport to warehouse or distribution point[1]

Figure 1.4 displays these steps in relation to production categories.


Figure 1.4 Charcoal Life-Cycle Screen Shot 2017-04-12 at 10.03.13 PM.png

Production Category #1: Resource Extraction

The process step of tree felling marks the starts of charcoal production. Workers use axes or chainsaws to cut individual trees down [8] [9]. Table 1.1 states some of the hazards and potential health consequences of this process step.

Figure 1.1 Resource Extraction Hazard Overview

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Production Category #2: Primary Manufacturing

During primary manufacturing, wood is prepared and dried for carbonization. The first step is limbing, which is the process of removing branches from the trunk of a fallen tree [10]. This is done using the same tools which were used for felling. After limbing is complete, bucking occurs. This is the process of cutting the felled trees into logs [11]. Then pieces are set to dry. After several days the wood is ready to be transported to the carbonization site. Tractors or carts pulled by animals are used to transport the wood [9]. During the loading and unloading stages, it has been observed that workers will stay on top of the woodpile helping to pass logs to other workers. Table 1.2 states some of the hazards associated with these process steps.

Table 1.2 Primary Manufacturing Hazard Overview

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To control the risks associated with wood piles collapsing, workers should not be permitted to be on top of them. This control is difficult to implement if workers are under pressure to complete a task as fast as possible. This pressure may lead to the non-compliance of rules which increase the amount of time needed to complete a task. It is important to note that most workers are paid in relation to how much charcoal they produce and not how much they work.

Production category #3: Secondary Manufacturing

The process steps involved in secondary manufacturing can be summarized as carbonizing the wood into charcoal. At the burning site batteries of kilns are set up [6]. Each battery contains six separate kilns. It takes approximately one day to fill and pack the kiln and two days for the carbonization process. Furthermore, between two and three days are needed for cooling and one day to remove the finished charcoal [6]. Thus six is intentionally chosen as the number of kilns for each battery as it corresponds with the carbonization process [6]. The idea is that there is always at least one kiln to be filled or emptied while the process of carbonization is taking place. The shape of the kilns can be described as cylinders with round tops [8]. In Brazil, they are typically made out of bricks and have two entrances. They also have a few smaller openings. Before workers begin the process step of filling the kiln with wood pieces, one entrance of the kiln is sealed with bricks and plastered with clay. This will be opened at the end of the carbonization process and be the exit for the charcoal. Workers pack the kiln with wood and seal the other entrance. Next, a worker climbs to the top of the kiln to start the fire.

During pyrolysis or the carbonization process, a worker is designated to monitor smoke observing its color and quantity [8]. The worker seals the smaller openings of the kiln with clay to control the intensity of the fire. It is crucial that the fire is just right for if the fire gets too intense, the entire kiln can collapse. As mentioned previously, the carbonization process takes around two days. Then the kiln is left to cool and at times water is poured on the kiln to aid the cooling process. The next step is to remove the charcoal from the kiln. Workers manually use wheelbarrows, metal baskets, shovels and pitchforks to remove all the charcoal from the kiln to a pile nearby. Table 1.3 presents some of the hazards and health consequences associated with secondary manufacturing of charcoal.

Table 1.3 Secondary Manufacturing Hazard Overview Screen Shot 2017-04-12 at 10.29.15 PM.png

A possible engineering control to reduce the risks associated with igniting the fire for the start of the combustion process is to build the kilns in such a way that enables starting the fire from the bottom [8]. An engineering control to reduce worker exposure to smoke during the pyrolysis process is to construct kilns with lateral chimneys [8]. Additionally, taking into account the direction of the wind when building the kilns may possibly reduce smoke exposure. An administrative control for this hazard as well as the hazard of ergonomic strain due to repetitive movements would be to rotate workers through various tasks. A simple, but possibly very effective method for increasing ventilation of the kiln when charcoal is being emptied is to open both entrances of the kiln [8].

Production category #4: Support Infrastructure and Power

One of the key support processes of charcoal production is kiln building. There are many types of kilns. The dominant one used in Brazil is built using bricks. The shape of the built kilns allows for uniform carbonization. Additionally, since the walls are in contact the outside air, uniform cooling is also achieved [12]. The hazards associated with kiln building can be generalized as fatigue or heat exhaustion. Skin lacerations may also occur. The processes involving brick production are worth examining.

Although not directly a process, the provision of adequate shelter, hygiene facilities, food, and water are very important in regards to support infrastructure as workers have very long shifts or are likely to be expected to live on site. Poor living conditions including the lack of provision of drinking water have been documented at many charcoal production sites [9]. This compounds the negative health impacts of the work itself.

Production category #5: Transportation

The first step of transportation is to load the charcoal onto the trucks. Workers fill metal baskets with charcoal and then place them on their heads to carry to the transport vehicles. They may have to climb a ladder with the basket in order to dump the charcoal into the truck [8]. If the charcoal is not intended for pig-iron production, it often has to be bagged. The process of bagging the charcoal can expose workers to a significant amount of charcoal dust [9]. Because workers transport charcoal on their heads, they may not comply with wearing any available head protection [9]. If the process of loading and unloading charcoal were to be mechanized, it would greatly reduce the manual labor associated with charcoal transport [9]. This can be categorized as an engineering control.

Most of the charcoal produced is transported by trucks to pig-iron production sites. Many charcoal production sites in Brazil are located in isolated areas which are far from major town centers. As a result, the roads to accessing them can be in poor state which increases the risk for road accidents [8].

Conclusion

There are many hazards associated with charcoal production. This project has only touched on some briefly. Given the great demand for charcoal, there is an obvious need for transitions away from traditional methods of production. In 2008, the International Labor Organization reported an estimate of 25, 000 – 40, 000 workers under conditions of forced labor and charcoal production was one of the prominent industries involved with forced labor [13] [14]. To combat this issue, the government set up a unit to perform labor condition inspections. This unit was able to rescue approximately 30, 000 workers over the course of fourteen years [14].

Additional Resources

References

  1. ↑ 1.0 1.1 1.2 Food and Agriculture Organization of the United Nations. (1987). Simple Technologies for Charcoal Making: Chapter 1 – Logistics of Charcoal Production. Retrieved from http://www.fao.org/docrep/X5328E/x5328e02.htm
  2. ↑ Girard, P. (2002). Charcoal production and use in Africa: what future?. Unasylva, 53(4), 30-35. Retrieved from ftp://193.43.36.93/docrep/FAO/005/y4450e/y4450e05.pdf
  3. ↑ 3.0 3.1 Olujimi, O. O., Ana, G. R. E. E., Ogunseye, O. O., & Fabunmi, V. T. (2016). Air quality index from charcoal production sites, carboxyheamoglobin and lung function among occupationally exposed charcoal workers in South Western Nigeria. SpringerPlus, 5(1), 1546. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5020008/
  4. ↑ 4.0 4.1 Müller, N., Michaelowa, A., & Eschman, M. (2011). Proposal for a new standardized baseline for charcoal projects in the Clean Development Mechanism. Perspectives Climate Change. Retrieved from https://cdm.unfccc.int/methodologies/standard_base/npbcharcoal.pdf
  5. ↑ Food and Agriculture Organization of the United Nations. (2016). FAOSTAT: Forestry Production and Trade. Retrieved from http://www.fao.org/faostat/en/#data/FO/visualize
  6. ↑ 6.0 6.1 6.2 6.3 6.4 6.5 6.6 Nogueira, L. A. H., Coelho, T. S., & Uhlig, A. (n.d.). Sustainable charcoal production in Brazil. Retrieved from Food and Agriculture Organization of the United Nations website: http://www.fao.org/docrep/012/i1321e/i1321e04.pdf
  7. ↑ International Iron Metallics Association. (n.d.). Pig Iron. Retrieved from http://metallics.org.uk/pigiron/
  8. ↑ 8.0 8.1 8.2 8.3 8.4 8.5 8.6 8.7 8.8 Kato, M., Demarini, D. M., Carvalho, A. B., Rego, M. A. V., Andrade, A. V., Bonfim, A. S. V., & Loomis, D. (2005). World at work: charcoal producing industries in northeastern Brazil. Occupational and environmental medicine, 62(2), 128-132.
  9. ↑ 9.0 9.1 9.2 9.3 9.4 9.5 Dias, Elizabeth Costa, Assunção, Ada Ávila, Guerra, Cláudio Bueno, & Cano Prais, Hugo Alejandro. (2002). Labor process and workers' health in charcoal production in Minas Gerais, Brazil. Cadernos de Saúde Pública, 18(1), 269-277. https://dx.doi.org/10.1590/S0102-311X2002000100027
  10. ↑ Wikipedia. (2017). Limbing. Accessed April 12, 2017 from https://en.wikipedia.org/wiki/Limbing
  11. ↑ Wikipedia. (2016b). Log Bucking. Accessed April 12, 2017 from https://en.wikipedia.org/wiki/Log_bucking
  12. ↑ Food and Agriculture Organization of the United Nations. (1987). Simple Technologies for Charcoal Making: Chapter 7 – Brick Kilns. Retrieved from http://www.fao.org/docrep/x5328e/x5328e08.htm
  13. ↑ Costa, P. T. M. (2009). Fighting forced labour: The example of Brazil. International Labour Office, Special Action Programme to Combat Forced Labour. Retrieved from http://www.ilo.org/wcmsp5/groups/public/---ed_norm/---declaration/documents/publication/wcms_111297.pdf
  14. ↑ 14.0 14.1 International Labour Organization. (2008, May 13). Forced labour in Brazil: 120 years after the abolition of slavery, the fight goes on. ILO Newsroom. Retrieved from http://www.ilo.org/global/about-the-ilo/newsroom/features/WCMS_092663/lang--en/index.htm

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