THE DAILY WORK LOAD OF REFUSE COLLECTORS WORKING WITH 3 DIFFERENT COLLECTING METHODS - A FIELD-STUDY

The daily work load of 116 Dutch (male) refuse collectors working with polythene bags, two-wheeled mini-containers and large four-wheeled co ntainers was studied. To this end a time analysis of the tasks and act ivities in the real working situation was made and the postures and th e physiological work load of the collector working with the three diff erent methods was assessed. Manual materials handling and the correspo nding working postures were studied by means of observations. Heart ra te (HR) was continuously recorded during the working day. Furthermore, to enable the assessment of the work load during refuse collecting as a percentage of the maximal oxygen uptake (VO2 max) every refuse coll ectors' relationship between HR and oxygen uptake was measured during a simulation of the tasks and activities in the laboratory. The range in total working time of the refuse collectors was large. Most time is spent on the task 'loading';this lasted on average about 5 h. The mea n number of handled objects for the three refuse collecting methods is 1500 bags, 500 mini-containers and 120 large containers respectively. The mean amount of collected refuse per collector of bags and mini-co ntainers is about 11 000 kg. For the collectors of the large container s it is 27% higher, namely about 14 000 kg. The mean weight of one obj ect for the bags, mini-container and lame container is 7, 22 and 110 k g respectively. The straight posture was the most common in refuse col lecting by bags. The posture flexed at the trunk and bent forwards or backwards occurred often while pushing and pulling containers. However , the refuse collectors of the large containers pushed and pulled for shorter periods during a working day in comparison with collectors of the mini-containers. Criteria for energetic overload were set at a mea n energy expenditure of 30% VO2 max and an energy expenditure of 50% V O2 max or more for a maximum of 60 min per day. According to these lim its the energetic work load of the collectors of bags was indicated as being too high. In order to formulate guidelines in terms of mechanic al and energetic load it is necessary to measure more accurately these loads during refuse collecting activities.