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Eleven MRFs were investigated as part of a European Commission BIOMED2 and Environment Agency joint-funded programme. These represented different recycling facilities currently operating in the UK. Three MRFs accepted household waste via kerbside boxes, two via a green bag, two from twin-wheeled bins and two accept waste from a combination of systems. The processing capacity for these MRFs varied from 1,000 to 100,000 tonnes per annum (t.p.a.), with ‘residue rates’ of between 8% (bags and boxes), to 60% (twin-bins and mixed) of the total throughput. This study was intended to investigate a range of occupational exposures to MRF workers, work-related symptoms and effects in MRF workers and potential environmental impacts.
As a result of a literature review identifying gaps in the knowledge in relation to MRF exposures (Nersting et al 1991, IEERR 1995, Sigsgaard et al 1996, Kivranta et al 1999), a variety of occupational and environmental measurements were made. Volatile Organic Compounds, Electromagnetic Fields, total and viable microorganisms, cadmium and mercury were not measured in significant amounts. However, concentrations of organic sulphur compounds below threshold levels could still contribute to gastrointestinal problems. Lead was detected in the air of one facility (2.5μg/m3), and was found in settled dust in all of the MRFs measured, but was not considered significant. Environmentally, noise and particulates were not detected in significant amounts, but retain a nuisance potential. Occupationally, noise was found to exceed recommended levels when operating some equipment and stereos, and required action from operators to protect operative’s hearing.
Also occupationally, dust, endotoxin and glucan were found in excess of recommended exposure levels (10 mg/m3 for dust, 10 ng/m3 for endotoxin and glucan). Self-reported symptom questionnaires on 159 operatives also identified that when MRFs were grouped into higher vs. lower exposure groupings adjusted odds ratios showed a significant increase in symptoms experienced by operatives with higher exposures. Relevant symptoms and exposures include dust and irritated nose (2.55 (1.20-5.70)); endotoxin with cough with phlegm (2.34 (1.11-4.93)) and hoarse/parched throat (2.62 (1.21-5.67)); and glucan with chest tightness (5.31 (1.37-20.56)), cough with phlegm (2.87 (1.26-6.56)) and stomach problems (4.53 (1.22-16.85)). To a lesser extent, operatives also complained of systemic problems such as headache and influenza-type symptoms, nausea and tiredness.
In the study, there was a significantly increased risk for self-reported respiratory symptoms related to higher work site exposures to endotoxin and (13)-ß-D-glucan. Gastrointestinal symptoms were related to (13)-ß-D-glucan exposure, gastrointestinal symptoms have previously been associated to (13)-ß-D-glucans and endotoxin exposure (Thorn et al 1998, Ivens et al 1999).
In addition in two MRFs monitored from start-up blood data from eight operatives new to the industry shows a significant decrease in lymphocytes (p=0.013), monocytes (p=0.001) and neutrophils (p=0.001) over a period of 10 months. This potentially reflects an inflammation in the lungs, where cells decrease in the blood because they are recruited to the lung as part of an inflammatory response.
The conclusions of this research are that biological agents present in the air at MRFs have the potential to be harmful to the health of operatives working in these plants. These occupational exposures are derived from close contact with waste materials, which exposes the worker to a localised aerosol of organic dusts from organic residues and contaminants (food and drink residues) within materials received. The effect of temperature and time on decomposition of these organic contaminants in the period after it is discarded and before collection may affect the amount of bioaerosols generated although no seasonal variations were detected in this study (unlike Thorn 2001). However, methods of handling materials were shown to affect exposure. Using chi-square tests comparing exposures in the MRFs, those that were twin-bin fed showed significantly higher exposures to dust and endotoxin, and also showed the highest amount of residue in the materials received.
This study recommends an interim approach to dealing with these potential issues until more data becomes available; exposures can be mitigated through a variety of measures. An overview of the possible solutions include targeting the quality of incoming materials, examining MRF design and materials handling, and ensuring regular housekeeping and maintenance procedures in conjunction with information, education and training on personal hygiene for MRF workers.
|Item Type:||Book Chapter|
|Keywords:||waste; recycling; health; bioaerosols; endotoxin; glucan; dust|
|Academic Unit/Department:||Faculty of Science, Technology, Engineering and Mathematics (STEM) > Engineering and Innovation
Faculty of Science, Technology, Engineering and Mathematics (STEM)
|Depositing User:||Toni Gladding|
|Date Deposited:||30 Jun 2006|
|Last Modified:||02 Aug 2016 12:57|
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