The Occupational Health in the Solid Waste Management

Jorge Ricardo Bernal.

Chemical Engineer.

Spanish version: La Salud Ocupacional en el Manejo de los Residuos Sólidos

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Introduction

All organized human activity is oriented towards obtaining a very specific purposes. Achieve these purposes with minimal effort in the shortest time possible and with minimum losses can be considered as a successful realization of such activity.

 
 

An Industrial Company has the basic aim of obtaining economic benefits based on an optimum productivity, ie the achievement of maximum production (in terms of quantity and quality), with the lowest possible cost.

In other words: Industrial production must be a profitable operation and this is achieved by:

1. Full use of all production elements,
2. reducing all unnecessary expenses,
3. loss control of all kinds.

 
 

Production Elements

1. Human potential: directive staff, technical staff, office workers, production workers, etc.
2. Facilities and equipment: buildings, vehicles and other physical elements which are not machinery.
3. Machinery: machine tools, auxiliary machinery, hand tools and other work items.
4. Materials: raw materials, intermediate products, finished products,
5. Time: Successful use of all remunerated time. The opposite case are the slowness in production, the “bottlenecks”, etc.

Within these production elements, the most important, not only from an ethical point of view, is the human potential to which should be given preferential treatment.

From the worker, the maximum of productive retribution is obtained when:

1. has made a good planning of its work,
2. has made an adequate personal selection and has been properly located,
3. is kept in the best state of physical and mental health.

It is possible to establish a parallelism with a Public Service Company whose objective is to offer an efficient service to the community through an optimized operation which involves:

1. the proper use of the production elements,
2. the minimization of unnecessary expenses or losses.

In any industrial company or service, productivity is reduced when the production elements are affected.

Occupational diseases and work accidents are disturbing factors that adversely affect on one or more of the production elements.

Will be eliminated or significantly reduced losses when a prevention program of occupational risks are established. For maximum effectiveness, prevention should start to be applied from the planning stage of the provision of a service, or product manufacture.

Several disciplines are dedicated to the prevention of diseases and accidents originated in the sites or for work reasons. Some definitions will help to identify them clearly.

Occupational Health

A joint committee of the World Health Organization and the International Labour Organization adopted the following definition in 1950:

“The Occupational Health aims to: promote and maintain in the highest level of physical, mental and social well-being of workers in all occupations; the prevention of occupational diseases caused by working conditions, personnel protection of the risks resulting from adverse health factors on the different tasks; the location and conservation of the workers in occupational environments according to their physiological and psychological aptitudes, in short:. the adaptation of work to man and of every man to their own work. “

Industrial hygiene

The American Industrial Hygiene Association has adopted this definition:

“The Industrial Hygiene is the science and the art dedicated to the recognition, evaluation and control of all those environmental factors and conditions that are originated in the workplace and can cause sickness,  deterioration of health and welfare, or significant discomfort and low efficiency among workers or between other citizens of the community. “

Ergonomics

A description by the International Labour Organization can be taken as a definition:

“Ergonomics is the application of science of human biology, together with the engineering sciences, to achieve the optimal mutual adjustment of the man and his work, the benefits can be measured in terms of efficiency and human welfare.”

To put it in another way, ergonomics will: ensure maximum operating efficiency, minimize the possibility of human error, reduce fatigue and eliminate, as far as possible the risk to the worker.

Industrial safety

The Industrial Security is dedicated to preventing the accidents occurrence, thereby avoiding all consequences or adverse effects.

The work accident is defined as an unexpected and undesirable event that originates in the occupational environment. Is the result of a failure in any physical element of the work or the unsafe performance of any person or group. May or not occur or not, personal lesions  or damage to facilities, equipment or materials. It anyway disrupts the normal progress of the work and is associated with downtime.

It is necessary to distinguish between “accident” and “lesion” because not every accident causes a lesion and because preventive action is oriented towards the causes of accidents.

The accident is the preventable event. The lesion is the ultimate consequence of some accidents.

From the study of the Occupational Health objectives, Industrial Hygiene, Ergonomics and Industrial Safety, is easily deduce that these disciplines contribute in the task of achieving the best performance of the human element and that in no way these can become a interference source  with the production or the provision of a service.

Contribute directly in reducing production costs. Hence may be expressed that a safe workplace is an efficient work and the simplest way to perform a task, is usually the safest.

Undesirable consequences

By the failure in the prevention of accidents and occupational diseases, many adverse effects will be presented:

1. People will suffer a deterioration in their health, illness, minor injuries, serious injuries and even death. Indirectly the productivity of individuals is affected, representing a loss for both workers and the company.
2. The property is affected because in accidents damage occurs in buildings, on the machines, tools, materials and other physical elements which are  needed for production.
3. In certain events, even though no injuries or material damages occurs, there will be a waste of time while also means economic losses.

Costs of Accidents

Is customary to divide them into two groups:

Costs A- “insurable”, sometimes called “direct costs” which are those easily identifiable as they correspond to specific expenditures. Examples of insurable costs are:

1. medical and hospitalization expenses.
2. costs per rehabilitation.
3. costs of compensation and disability benefits.
4. costs for funeral services.
5. the costs of repair or replacement of the goods that were damaged in the event.

B- “non insurable” Costs, also called “indirect costs” which are more difficult to establish since they are not directly accounted. Examples:

1. time wasted in the attention of cases that require first aid.
2. time to transport injured to hospitals.
3. lost time (paid) by the injured worker.
4. nonproductive time of non injured workers that stopped their work to help or to observe the injured and the damage caused by the accident.
5. time spent on cleaning up the area where the accident occurred.
6. time consumed to organize the resumption of the work interrupted by the accident.
7. overtime needed to regain the time lost of normal production.
8. low performance of the injured when he returns to work or during replacement’s training.
9. time spent on the investigation of the accident causes, on filling out forms, etc.
10. intangibles such as crushed spirit of the workers that were witnesses of the accident (low productivity); an increase in labor disputes (for high accident rates); adverse public relations, etc.

Non insurable costs exceed insurable costs by a factor that can be between 4 and 10 or a much greater value.

Whenever an accident occurs, individual productivity, the productivity of the company and the national economy will be directly or indirectly affected.

All of the foregoing constitutes an incontrovertible argument to adopt within the whole company, a program of accident prevention and occupational diseases.

Organization of the Programme for the Prevention of Occupational Risks

In order to achieve the objectives of:

1. avoid the accident occurrence  and diseases
2. reduce operating costs or production should be taken into account these key points:
   1. location of the program within an organization chart.
   2. the policies of directives on the subject.
   3. the formation of a multidisciplinary team.
   4. the active participation of all members of the company or entity.

1. Location of the program within an organization chart

The activities of the Occupational Health contribute to efficient production and are not a cause for interference.

The functions are advisory in nature rather than executive. Thus, the worker will receive orders only from the hierarchical superior.

If Occupational Health technicians find an immediate risk to workers, they will not try to order the suspension of work but will report to Chief of Section, Department or Group, for the dangerous condition is corrected. If this person is sufficiently reasoned, will attend the suggestions and will obtain an appropiate result without causing any trauma.

Obviously that will always have the advise of those responsible for advancing the occupational health program.

From the above it follows that the location of the programm in the organizational structure, will be of an advisory body of directives without executive powers. Should depend on the management or other top-level executive, who has the ability to make decisions about the program. A direct communication, without intermediaries, is one of the basic factors for the good progress of its activities.

Similarly, it should have contact with all heads of department or section to advance together in many phases of the integral plan.

2. Policies of Directives

It is essential that company policies explicitly express that the prevention of occupational risks is an important objective of the organization and fully support the program and its executors.

The positive attitude of the directives is manifested in several ways:

1. promoting communication so that information on safety issues  and industrial hygiene reach all sectors of the company.
2. participating in health and safety committees to have direct knowledge of what is discussed there.
3. orienting regarding the selection of staff.
4. organizing the training program, as the technical aspects with health and safety in the work are integrated.
5. encouraging the individuals or groups who stand out for their behavior in line with health and safety standards.

3. Multidisciplinary Human team

The complexity of the problems involved require the cooperation of several disciplines. The basic team will consist of engineers and doctors in the areas of industrial hygiene and safety and industrial medicine.

According to the characteristics of the processes and inherent risks, it may be necessary to complement the group of specialists with chemistries of industrial hygiene, ergonomists, industrial toxicologists, psychologists, epidemiologists, etc.

Considering the shifts and the presence of certain risks, staff can be full time or part time.

4. Participation of all members of the company

Within a well organized entity, none of its members can be considered outside the program for the prevention of occupational risks. In greater or lesser degree, every individual has a direct or indirect relationship with the program.

In groups is possible to define specific functions, thus:

1. The company directives should:
   • Provide a safe place to work.
   • Issue a Health and Safety Regulation.
   • Establish mechanisms so that workers:
     • receive instruction on how to work in a secure way.
     • be monitored to verify compliance with the respective standards.
     • are motivated so they provide effective collaboration.

   • Periodically visit job sites in order to learn directly from the march of some phases of the problem.

2. The heads of department or section, supervisors or team leaders will have to:
   • Knowing the Health and Safety Regulation.
   • Be aware of the risks and preventive methods and control.
   • monitor workers to perform with maximum security.
   • Provide guidance and example for subordinates, with their positive attitudes towards the program.
   • Take steps to correct the  risk conditions and unsafe acts.
   • Organize activities of routine maintenance and preventive maintenance to ensure safe work conditions.
   • Coordinate actions in case of accidents with injury, in order that those affected receive prompt medical attention.

3. Workers are responsible for:

   • Comply with Regulations on Health and Safety.
   • Know and apply the safe procedures at work.
   • Collaborate in the activities of the Health and Safety Committee.
   • Report as soon as possible the existence of hazardous conditions.
   • Report the accidents occurrence and seek medical attention, even in cases where the injury is slight.

Investigation of the Causes of Work Accidents

A common mistake when the causes of accidents are investigated is the lack of depth or be satisfied with a hasty identification of the immediate causes, which are sometimes apparent and disorient the adoption of corrective or preventive measures.

The first attention, sould be towards the unsafe act, unsafe environmental conditions or both, then it is indispensable ask the question: why? (why the unsafe act or why the unsafe condition).

The response provides information that will identify the mediate causes, if there are, this way you will be able to conduct an effective action upon the true causes of the accident.

The scheme presented on page 13 is called ” flow diagram of the anatomy of accidents,” which attempts to show on an orderly manner, the sequence of events for an accident. Starting from the consequences can be reached the causes.

Experience shows that 80% of accidents has its origin in the human factor and 20% in the environmental factor. This suggests that preventive program must give primary importance to the correction (or prevention) of unsafe behavior of workers.

The identification of the causes of accidents can be reached through two procedures: retrospective and prospective.

The retrospective method is based on the investigation of accidents within the company. It is not uncommon that the investigations were limited to cases where there has been a disabling injury. Being strict, the investigations should be advanced for all events covered in the technical definition of accident.

Two limitations should be mentioned for the retrospective procedure: (a) is necessary to wait for accidents to identify causes; (b) the preventive actions will be only for accidents similar to the ones occurred before.

The prospective or anticipatory method, also called risk analysis is based on the identification of potential risks to guide the adoption of preventive mechanisms before accidents occur. It has the advantage of covering the widest range of probable accidents.

The procedures are not mutually exclusive and may be used in practice a combination of both, which is highly recommended.

Research Methodology

Summary on the topics to be covered in the investigation of the causes of workplace accidents:

1. All accidents must be investigated regardless the severity of the consequences.

 

2. The investigation will advance at the earliest opportunity. Delays even if they are short, allow the evidence to be destroyed, removed or details are forgotten by the witnesses.
3. The investigation will be conducted by one or more of the following:
   1. the immediate superior of the injured.
   2. a member of the Industrial Security dependence  or a member of the Health and Safety Committee.

4. Researchers will have as a guide these principles:
   1. Objectivity and order (use a format).
   2. Do not despise no clue.
   3. Checking the existence of conditions and / or unsafe acts.
   4. Prepare a written report, which will contain suggestions for corrective actions.

5. Get as much information as possible from:
   1. the specific site where the accident occurred (geographic location).
   2. data about the personal involved (level of education, work experience, age, etc.).
   3. all data about location over time (hour, shift, day, etc.).
   4. what was doing the worker immediately before the accident (is the usual occupation?).
   5. the involved physical elements (machines, tools, materials, other objects).
   6. the reasons why, there was an unsafe condition or an unsafe act is performed.

Quantitative appreciation of the Accident Rate

When you have a measure of the accident rate will be possible:

1. comparisons with other similar companies.
2. check if the safety program remains in line with the changes made (processes, environmental conditions, etc.).
3. to appreciate the effectiveness of the corrective methods that have been adopted.

Are widely accepted the Frequency Index (of accidents) and the Severity Index (of injuries), whose definitions are stated below:

I.F. = Number of Disabling Injuries x 10^-6 / Number of man – hours of exposure.

I.F. = Index frequency to monthly or annual periods (cumulative).

Disabling injury = is when the time lost is one day or more.

Man-hours of exposure = is obtained in an accurately way, or by estimations.

This index has the disadvantage of not including accidents without injuries which are very numerous.

Based on statistics, Heinrich (1931) and Bird (1966) established the relationships:

I. G. = Total number of days missed or loaded x 10^-6 / number of man – hours of exposure.

I. G. = Severity index for annual periods.

Days missed or loaded = true days of incapacity plus penalty when there is total or partial permanent disability.

Number of hours – man of exposure = exact or estimated value.

Risk Analysis

The method is applicable for activities that are not yet performed, which means an intervention of the security program on the planning stage of tasks. This situation is the most advantageous possible.

It also applies on operative companies. In this case is made in advance a detailed study of the potential hazards, through careful observation of staff in the effective performance of its functions.

The risk analysis may be qualitative or quantitative. The first is a non-mathematical review of all factors that can affect the man machine system. Are not included studies of probability of accident occurrence.

The purpose is to achieve maximum safety conditions by eliminating or minimizing risks without taking into account the probability of occurrence for adopt the methods of control.

The search for the probable risks by environmental factors (physical conditions of the work environment) is oriented:

1. identifying the inherent properties or characteristics of equipment, substances, etc., in direct contact with the workers.
2. identifying possible failures of such elements.
3. specifying the level of effort required by the executed tasks.

The search for potential risks by personal factors (human error) could be oriented:

1. identifying the predictable errors and random errors (those difficult to predict).
2. identifying the primary errors, ie those of the person or group directly related with the activity; these are the operating errors.
3. identifying the contribution errors which are committed by other person or group; these are the errors of design, manufacturing, maintenance etc.

In any risk analysis are evaluated:

1. mutual relations between the primary risks and contribution risks.
2. condition of equipment and personnel on the man machine system (movements, efforts, proximity to the risk point, etc.).
3. mechanisms to eliminate or control risks (special design, appropriate materials, etc.).
4. the fittings that may be required for safe operation ( machinery guards, personal protection equipment.
5. the possible adverse effects that can result when control is lost on those risks which could not be removed.

A Quantitative analysis may be necessary to determine: (a) frequency of occurrence either probabilistic or relativistically; (b) Risk magnitudes; (c) costs included.

Relativistic analysis

In this type of analysis is made to intervene the approximate frequency with which a specific adverse event occurred with existing operational elements. The gradations ( remote occurrence, random, rare and chronic ) are based on experience with similar components systems or are based on the results of preliminary tests on parts of the system under study.

Probabilistic analysis

It is a determination of the security level  of a system or subsystem in which the result is expressed in terms of probability.

A probability is the expectation of that an event occurs in a certain number of times in a specified number of trials.

The method considers that the security level of a system or subsystem in operation may be indicated by determining the probability that accidents, will be caused by specific risks or combinations of risks, whose presence have been established through qualitative analysis.

The probabilities are obtained through operative experiences of similar systems, by preliminary tests, etc.

Some objections to this procedure:

1. a probability, as reliability, guarantees nothing. The probability indicates that an error or accident is possible, even though is rare the occurrence in a certain period or for a considerable number of operations. Is unfortunate the fact that the probability does not indicate when it will happen.
2. Ethically it can not be justified the existence of an uncontrolled risk, no matter how high the probabilistic level of security can be.
3. the probabilities are projections calculated from statistics obtained from experience. Although the study equipment is the same with which these statistics were obtained, the conditions under which it will operate may be different.
4. human error may have detrimental effects, even if reliability of the equipment has not declined.

I- About Human Factors

>The unsafe behavior of workers can be prevented, when organizing activities in the fields of:

1. selection and personal location.
2. education and training.
3. motivation and promotion of the program.
4. control the factors that have been originated outside the work environment.

a. Selection and personal location

The selection in a positive direction, aims to highlight the capabilities and skills of applicants in order to locate them correctly (if there are more positions) or to check that these attributes match the requirements or exigencies for a particular task.

If physical or mental deficiencies were discovered, it will not disqualify the person for all kinds of work, but will avoid to locate this worker where his condition can worsen, or where can come to constitute a risk to himself or coworkers.

Using a variety of tests and physical and psychometric testing is possible to obtain the desired information.

b. Education and training

Except for reflex and instinctive actions, may be expressed that human acts are learned. Therefore, the safest way of action can be learned. This fact is quite significant and is the cornerstone of any program of education and training.

Education aims to create a receptive attitude towards the prevention of the different occupational risks.

By selection, you will be able to  choose suitable individuals with certain skills, but they probably do not possess the adequate preparation. For this reason it is required to subject them to a training program which will provide expertise and additional skills as part of plan of mutual accommodation between elements of the human-machine system, emphasizing in the postulate that production and safety are an indivisible unit.

Several principles should be kept in mind when training is programmed:

1. There must be some interest by the worker. You can not learn when there is no reason to do so.
2. Instruction should be methodical and gradual, considering that there are individuals who assimilate knowledge slower than others.
3. The staff will be more receptive when you have fully understood the reasons why a task must be done in a certain way.
4. There will be a complete agreement between the theoretical and practical aspects. In addition to clearly articulate the stages of the safe procedure, will be taught how to do things, in order to develop safe habits.
5. The best practical training will be in the actual performance of work, initially with a very close supervision, for immediately correct the errors likely to be committed.
6. Part of the training will be to make known to the worker The Regulation on Health and Safety of the company in order to become familiar with it from the beginning of his employment relationship to the entity.

To avoid losing efforts in the staff training phase, there will be regular monitoring.

c. Motivation of workers

Without the cooperation of the workers will be very difficult the satisfactory progress of the program. The degree of cooperation is directly related to motivation.

Through coercion or the threat of sanctions is possible to achieve a cooperation more apparent than effective. A policing monitoring is required, with all the limitations that this represents, to ensure that standards are met.

The ideal would be achieve voluntary cooperation, by conviction, which has a character of firmness and durability. Its pillars will be:

1. the concepts they have about the job.
2. the knowledge that the directors of the company are interested in defending the physical and mental integrity of its workers.
3. the recognition that there are advantages for all in the safe execution of daily tasks.
4. the existence of incentives (of various kinds) to compensate the safe performance on tasks.

It is considered appropriate bring up some ideas related to the numeral 1. On page 145 of the book “Business and men”:

“For some the work, especially the material is presented as a punishment from God or as a way to bring the material part of man to servitude of his spirit. The work is a conviction, a penance, a form of purification.”

“For others, however, work is an essential constitutive of human nature, is the expression and self-realization of human beings. For the same, work must be itself a source of satisfaction.”

“All work is noble, due to it is the manifest and self-realization of men.”

Certain tasks may seem for some, unimportant or even degrading. The ones in charge of performing these activities may feel frustrated and completely crushed spirit. The lack of motivation will prevent any cooperation.

The negative attitude can be turned into something positive if the worker manages to understand that their work is important within the company; that the proper functioning of the entity will depend on the individual and team contribution of all its members.

Another issue that must be submitted to the consideration of the directors and workers is about the personal requirements and selection.

A labor decreases in its category when you have the idea that: it doesn’t requires  special personal conditions to be performed, therefore it is not necessary to make a selection; that to this position come the people who have failed to demonstrate skills in any other profession.

All these thoughts discourages the workers and contribute to the increase of the accident rate and to the reduction of efficiency at work.

In the particular case of workers who collect solid waste there must be a selection because the tasks require certain personal conditions. If this is known by the staff, will be a source of satisfaction having passed through the respective tests and have been chosen to join the company.

The interest in the issues that have been discussed, have to be something permanent, so that in order to keep a good spirit of collaboration, the use of advertising methods is made. These are mechanisms of effective help:

1. The use of posters to remind precautions, safe methods and the use of personal protection equipment.
2. The publication of a newspaper with brief information on risk prevention.
3. The establishment of contests as healthy competition between the different areas.
4. The workers participation in the Health and Safety Committee of the company.
5. Frequent contact of specialists on health and safety with workers, to advise them on the respective problems.

d. Control of factors originating outside the work environment

The correction of these disturbing factors originating outside the workplace, that prevent the good staff performance in their daily tasks should be cause for attention from the directors of the company.

A large part of special benefits such as medical care for the relatives, house plans, education plans, etc., help to solve many problems outside the work and represent an advantage as they reduce the stress that prevents workers focus their attention on their tasks.

II- About the Environmental Factors

It is relatively more easier to correct environmental or physical failures that the faults related to human factor. But this does not mean that the adoption of measures requires little effort or little investment.

In the control of environmental factors a depth technical knowledge is applied and it is not uncommon to find very high costs.

In general, the environmental control can be summarized in the following points:

1. The ergonomic design of the environment and tasks. The mutual relations of the components of human-machine system must be taken into account. It will take advantage of the skills and abilities of the human element, without forgetting its physical and psychological limitations.
2. The adequacy of the workplace to provide a safe and comfortable environment, in a way that it becomes a desirable place where personal satisfactions are found. The adoption of mechanisms to successfully fulfill a program of routine maintenance and preventive maintenance.
3. The selection of the most suitable, comfortable and reliable elements for personal protection when they become necessary for the defense of its physical integrity.
4. As a complement, a very close attention must be paid to the monitoring of workers by conducting frequent visits to work sites to discover and correct unsafe conditions and practices.

Investigation of the Causes of Occupational Diseases

To identify the causes of diseases originated at work, two methods are used:

1. the prospective method or Risk Analysis.
2. Retrospective method or epidemiological.

a. Risk analysis

The identification of the causes of occupational diseases includes qualitative and quantitative aspects. Requires a detailed knowledge of operations and production processes to discover which agents are susceptible to have contact with the workers and thus exert their negative effects. In addition, it is required to determine (based on environmental measurements or by estimations) the extent of exposure. In this quantitative assessment will be based the need or not, of adopting preventive methods or control.

The quantitative assessment is based on data or relative values. Data from measurements or the estimations are compared with the permissible exposure levels to express the result as a relative value, much more useful than a absolute value.

The toxicological research highlights the adverse biological effects of chemical compounds (raw materials, intermediate products, finished products, waste products) used in industry and focuses on the application of environmental control methods and medical control.

b. epidemiological research

Requires a systematic study of the available information on morbidity and mortality, to perform a correlation with data on environmental measurements. Tries to discover the cause-effect relationship between environmental agents and consequences present in the exposed personnel.

As can be seen in this description of the method, the occurrence of cases of illness or death is required to apply it. If can be proven the causal relationship, research will serve as a very strong support for preventive measures and control.

In a similar way as with work accidents, is presented below a flowchart of the genesis and effects of occupational diseases.

Environmental Control of Occupational Diseases

The most effective control is the one applied at the origin of harmful agents (examples: substitution, isolation, exhaustive local ventilation systems).

When it is not possible to control at source, The control is made at the transmission medium (examples: General ventilation by dilution, increasing the distance in protective screens).

Only if a complement is required, it will be advisable the use of personal protection equipment (respirators, earmuffs, gloves, etc.). The use of these elements comprises many limitations, being the principal, that the risk is not eliminated. Therefore should not be considered as substitutes for primary control methods but as a complement.

Medical Control of Occupational Diseases

Summary on medical control measures:

1. Conducting pre-employment tests for the personnel selection and to guide its location.
2. Programming and conducting periodic reviews with a frequency that will depend on the type of risk to which personnel is exposed.
3. Research on the potential risks that offer new processes or equipment to be incorporated.
4. Toxicological and diagnostic studies of occupational diseases.
5. Collaboration for adopt personal protection elements.
6. Participation in health education activities for workers and guide the training for the proper provision of first aid.

Risk in Activities of Collection and Transport of Solid Waste

It was stated at the beginning of this paper that there are coincident aspects between industrial companies and utilities.

It is also necessary to clarify that differences occur in working conditions, especially for the group responsible for the collection and transportation of solid waste. These points are:

1. The workplace is changing. It is constituted by public roads. due to the environment is not owned by the utilities, it is almost impossible to keep a control on it.
2. There are Special risks (interference) due to they are unable to isolate the workplace but rather must necessarily work in direct contact with the public (pedestrians, drivers with their own vehicles, etc.).
3. Is quite complicated to exercise a careful supervision on the staff in the performance of their duties.
4. a high percentage of workers corresponds to unqualified personnel (with failures in education and preparation) which increases the chances of an accident.
5. in the event of an accidental injury, it is generally difficult to provide timely assistance (first aid). There will be a delay in getting medical care and this loss of time can sometimes be fatal.

Unfortunately it is very limited the information in our setting on the occurrence of accidents and occupational diseases in the tasks of collection and transportation of waste.

This is the reason why, it has recurred to present some data of accidents, from abroad. Such information is considered useful because you can see the importance of the problem.

In the United States, cities with over 100,000 inhabitants have published data relating to an exposure time of more than 16.5 million man-hours.

The frequency rate for disabling injuries was 60.7 and the severity index 2012. The frequency rate is almost 10 times the value for the industry in general (6.12). The severity index for the whole industry was 682.

Is deducted that the activities of the personnel of the Public Companies are ranked among the ones with the higher risks. This phenomenon can easily be extended to our environment.

a. Load Handling (waste containers, etc.)

There is no general regulations in the country, about the shape, size or capacity of the containers to collect solid waste. But even if there is some notion of maximum weight of containers, risks of injury (especially back problems) would remain in place, if appropriate methods for the manual handling of loads are not taken.

b. Vehicles for the transport of waste

It is common in our environment to use open trucks or trucks that have many disadvantages:

1. the aesthetic appearance leaves much to be desired.
2. waste can easily fall to the floor and disperse.
3. at least one worker must remain above the cargo to receive and empty the containers and to accommodate waste. There is a risk of falling and direct contact with the waste is unhealthy.
4. usually the vehicle don’t have secure means of access to the top.
5. vehicles have no stirrups and handles for safe transport of personnel on short trips.
6. Typically, the collection staff, move running down the street, representing a serious risk of falls.

c. Multiple Hazards

1. Skin affections including: abrasions, cuts, puncture wounds, lacerations, burns, etc.
2. Being Run over with all kinds of vehicle due to have multiple points of attention at the same time; uniform with a low highlighted color; recklessness of drivers.
3. Trips and falls by: the number of objects in the streets; the poor condition of the floors; the running practice instead of walking due to the need to adjust to the travel speed of the waste collection vehicle.
4. Strikes against waste containers and against countless objects of all kinds, present in the tour.
5. Dog bites, rats and other animals.

Risk Control – Technical Aspects

a. Load Handling

This issue is of such importance that it is necessary to give detailed information. As an Annex is included a guide for manual handling of loads.

b. Transport vehicles of waste

Should be made every effort to replace the improvised vehicles with closed compactor vehicles. Using these mechanical devices brings several advantages in terms of comfort (efficiency) and sanitation but, like in all mechanical medium, there are other type of risks for staff. You need to plan these tasks. Some aspects are stated in a summary form:

1. staff must receive prior instruction about the risks and how to safely operate the equipment.
2. The location of the switches or controls will be indicated to the workers to stop the movement in an emergency.
3. It is recommended that the controls are capable of reverse the transfer mechanism and compaction, to be activated if any worker is accidentally caught.
4. in normal operation, only one of the group members will operate the mechanism. Others, will stay away.
5. controls shall be located at the rear end of the vehicle, where the operator can have full visibility of all mobile elements.

Stirrups and handles: they will be placed in the rear of the vehicle. The height of the stirrup over the floor will be 30 to 35 centimeters. The width must be sufficient to provide a good support but not excessive in order to prevent that workers, hit their legs with it. The handles should be accessible regardless of the stature of workers.

This form of personnel transport is acceptable only for short trips.

Vehicle signals: when workers are on the stirrup should not obstruct the visibility to turn signals, detention or indicative of backtracking.

The exhaust gases: the expelling of engine combustion gases whose components are harmful, especially carbon monoxide should be above the cab to not go directly to the breathing zone of workers.

Speed: Instructions wil be given to the drivers to maintain a speed in which staff does not have to run all the time.

Vehicle Maintenance: recommendations related to industrial safety:

1. Only authorized personnel shall drive the vehicles.
2. it will be ensured that there is good communication between the driver and the rest of the group.
3. before starting to work, it will be checked at least the state of the vehicle steering, the conditions of brakes, lights and mechanisms of transfer and compaction

c. Personal protection equipment

Before providing this kind of protection is necessary to advance in a campaign of education and motivation in order that these items can fulfill their function.

it will be explained to the workers the existence of certain risks; the necessity of use of protection elements; it will be shown how to use them correctly, it will be mentioned how to determine when they are failing.

The selection of these elements must be done very careful. Should guide its acquisition quality and not just the cost

It will establish a Proper maintenance service for these items.

Guide on protection needs:

1. head:
   • shock resistant helmets, not necessarily dielectrics.
   • Appropriate respirators when are needed.
   • Handkerchiefs and rags are not substitutes for respirators.
2. hands:
   • leather gloves with palm reinforcement;
   • rubber gloves with cotton interior lining, and palmar external reinforcement with a rough surface for good grip.
3. feet:
   • safety shoes with steel toe and slip soles.
4. trunk:
   • uniform made of resistant fabric and double seam; highly visible colors (yellow, orange, greenish yellow).
   • Right size without being too tight. short sleeve is preferred or long sleeve with tight fists.
   • Narrow and smooth boot (no bending).
   • No loose parts (spare clips).
   • Leather patches on the shoulders and hips (according to the form of moving the objects).
   • Raincoats for rainy weather, light-colored or dark with yellow or orange stripes.

Risk Control – Medical Aspects

Already been discussed regarding the involvement of medical professionals in the staff selection, the location of new workers; in performing periodic examinations; in the training of personnel for the adequate provision of first aid.

It also corresponds to Physicians, guide and perform a routine vaccination program; advance on health education campaigns (induce workers to take a shower at the end of the working day, and to create the habit of washing hands before eating etc.).

First Aid: Because of  the work characteristics of solid waste collection, where no one have a permanent place to labor, it is necessary that all staff receive training in the application of first aid to the injured.

Emergencies arise anywhere, far from the medical dispensary; If the assistance provided is inadequate, it may cause serious harm to the victim.

Can not be expected to conveniently apply artificial respiration, a tourniquet or technically moving a fractured, if you have not received a good capacitation.

Corresponds to the medical service, organize this type of specialized training.

The medical staff will decide on the convenience or not that every vehicle have a first-aid kit and, if so, will indicate their content.

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Bibliography

International Occupational Safety and Health Information Centre (CIS) – Information Sheet No. 3 – “Manual Lifting and Carrying” – International Labour Office. Ginebra, 1962.

Fawcett, H.H. and W.S. Woods, editors – “Safety and Accident Prevention in Chemical Operations” – John -Wiley and Sons, New York, 1965.

Organización Internacional del Trabajo – “La Prevención de los accidentes” – Ginebra, 1970.

De Montmollin, M. – “Introducción a la Ergonomía. Los Sistemas Hombres- Máquinas” – Aguilar, Madrid, 1971.

Hammer, W. – “Handbook of System and Product Safety” – Prentice Hall, Inc. Englewood Cliffs, 1972.

Suárez, Reinaldo – “Empresas y Hombres” – Editorial Centro Don Bosco. Bogotá, 1974.

Mc Cormick, E.J. – “Human Factors in Engineering and Design” – Tata Mc Graw- Hill Publishing Co. Ltd. New Delhi, 1976.

Association Générale des Hygiénistes et Techniciens Municipaux – “Técnicas de Higiene Urbana – Recogida de Basuras – Limpieza de las Vías Públicas” – Instituto de Estudios de Administración Local. Madrid, 1977.

Handley -.”Industrial Safety Handbook”, 2nd edition – Mc Graw- Hill Book Co. (UK) Ltd. England, 1977.

Clayton, G.D. and F.E. Clayton – “Patty’s Industrial Hygiene and Toxicology”, 3rd edition. Vol. 1 John Wiley & Sons. New York, 1978.

Margolis, B.L. and W.H. Kroes – “El Lado Humano en la Prevención de Accidentes” – Editorial el Manual Moderno, S.A. Mexico, 1979.

Human resources are the most valuable asset on a company or entity. Shall be protected and preserved in optimal conditions by the proper application of the principles of occupational health.

Annex – Economic Guide for load management

When it comes to manually mobilize different types of objects, it is necessary to take into account besides the respective weight variables, the ones listed below:

1. Variables related to the task:
   • weight,
   • size and shape of the object,
   • height,
   • distance and
   • lifting frequency of the objects.
2. Variables related to environmental conditions:
   • temperature,
   • humidity,
   • air movement,
   • presence of agents that contaminate the air.
3. Variables related to the human factor:
   • age,
   • sex,
   • physical conditions,
   • assumed posture.

Characteristic lesions in responsibles for the manual handling of loads:

1. Back problems, with acute or chronic lesion in the sacrospinalis muscle and intervertebral discs. The risk of injury increases when are combined an overexertion with degenerative changes in the back by because of advanced age or pathological changes.
2. Abdominal hernias of various kinds, depending on the magnitude of the effort.
3. Fatigue from a repetitive work; fatigue may be the source of many accidents.
4. Foot injuries from falling objects that are being mobilized especially when not using safety shoes (steel toe).
5. Aggravation of circulatory and respiratory diseases.

Risk assessment:

1. Are considered: the weight of objects that are lifted and the frequency with which this operation is performed.
2. The method employed: there are damages even with light loads, if your back is bent, using mainly the weak muscles.
3. Worker Age: will be greater risks if very young or elderly workers are employed. The recommended age is between 20 and 35 years.

The table below shows the effort that supports the fifth lumbar disc when back bends without lifting loads or lifting some weights.

Table No. 1 – Efforts on the fifth lumbar disc.

Allowable loads:

The International Labour Organization suggests as maximum the following values when, lifting loads is an occasional work:

Tabla N° 2 – Límites razonables para izar cargas.

 

It is essential to make a very careful selection of staff and perform an adequate training in the event that is required the frequent mobilization of loads with weights above the values specified in this guide.

Another key aspect is how the objects are lifted and moved. The respective recommendations are presented below:

Method for the proper handling of loads

1. Estimate the weight of the load. Do not try to go it alone if you think is too heavy. Do not feel embarrassed if you need to ask for assistance.

 

2. Make sure you have a good support on the floor. The body should be well balanced.
3. Be positioned as near as possible. The feet may be 30-40 inches away from each other. It may also be one foot forward and to the side of the object.
4. Bend your knees and crouch as if to sit down, keeping your back straight. If necessary, get down one knee to be even closer to the object.
5. Grab correctly. There must be a palmar grip for safety. Thus not weak muscles are used and also keeps the arms straight.
6. Begin to get up using the muscles of the legs and arms (which are powerful) and not the back (they are weak). This way the inertia of the object is defeated. The use of this movement allows to: that the body weight is advantageously used, that a little effort has to be done, and that there is little possibility of injury.
7. Lift the object to the transport position, always trying to maintain a straight back and carrying the load close to your body. Keep your arms as close to the trunk as possible.
8. If you need to change direction, do not twist or rotate the trunk, but the whole body by varying the position of the feet.
9. The chin behind. Lesions of the intervertebral discs are not limited to the lumbar region but also occur in the cervical region. By retracting the chin, head aligns with the body and the injury possibility is reduced. This position facilitates breathing during exercise.
10. Maintain good visibility over the object that is being mobilized. You need to see where you walk to avoid tripping or falling.

In contrast, in the figure is shown one of the not recommended ways for lifting objects even if they have a light weight.