Journal of School of Public Health and Institute of Public Health Research

Efficiency of a repeated fed-batch bio-reactor with powdered active carbon for landfill leach ate treatment

S Jorfi

Background and Aim: High concentrations of organic compounds and ammonia and entry of toxic pollutants lead to a low efficiency of direct biological treatment of landfill leachate. The aim of this study was to determine the efficiency of a repeated fed-batch biological reactor with powdered active carbon (PAC) for landfill leachate treatment.

Methods and Materials: Raw leach ate was pretreated by coagulation and flocculation processes and, then, the ammonia was removed by air stripping at a high pH, before biological treatment. The pretreated leach ate was treated bio-treated in an aeration tank by the repeated fed-batch method. Three cycles of 1×40, 5×8, and 4×10 hours were attempted in the absence and presence of 2 g PAC /L.

Results: Results indicate that the presence of PAC increased the COD removal efficiency significantly. The initial COD effluent was 3900 mg/L. Its values were 169 mg/L and 622 mg/L in the presence and absence of 2 g/L PAC, respectively, for the cycle of 5×8 h.

Conclusion: Based on the results of this study and findings of other investogations in this field, it can be concluded that repeated fed-batch bio-reactor has is quite effective for treatment of pretreated leachate.

Assessment of ergonomic situation of workers in a dam construction workshops using the NIOSH-CPWR Checklist

J Nasl saraji

Background and Aim: The large volume of reports and statistics in the literature on the prevalence of musculoskeletal disorders (MSDs) in Iran and other countries indicates that it is essential to assess the ergonomic situation in different occupations. These disorders can be caused by long-term exposure to different agents or by trauma to the musculoskeletal system. A large part of the work force in Iran is engaged in general construction and dam construction workshops. The postures of these workers while working in the workshops are unsuitable postures. The objective of this study was to assess the ergonomic situation of workers in dam construction workshops.

Methods and Materials: This was a cross-sectional study conducted in 2008. The sample included 110 randomly selected male-workers in a dam construction workshop in Takab City, Iran, engaged in 25 different jobs. Data were collected using the Nordic Musculoskeletal Questionnaire and the National Institute of Occupational Health-Center to Protect Worker Rights Checklist (NIOSH-CPWR), both developed by the National Institute of Occupational Health-Center to Protect Workers Rights. The software used to analyze data was SPSS.

Results:The average service record of the workers was 36.6 ± 86.8 months. The data show that the most common (55.5%) MSDs were in the low back region. There were statistically significant positive associations between prevalence of MSDs and many independent variables, namely, age, weight, education level, service record, smoking, type of job, lengths of time of standing and sitting at work, total duration of work, work pressure, undesirable postures, and surface for walking.

Conclusion: The results of this study generally confirm findings of previous investigators. It can be concluded that ergonomic assessment of jobs may give valuable information to be used by occupational health and safety authorities in planning preventive and educational programs.

Assessment of the efficiency of Health Services Workshops in Iran using linear programming

J Rezaee

Background and Aim: By definition, the ratio of output to input in any firm is called efficiency. In general, there are two main approaches for measuring efficiency ─ parametric and non-parametric. The objective of this study was to assess the efficiency of Health Services Workshops in Iran in 2006.

Methods and Materials: The efficiency of Health Services Workshops in Iran in 2006 was assessed using the non-parametric method, based on linear programming. More specifically, the Data Envelopment Analysis (D.E.A) was used. The most important feature of the Data Envelopment Analysis (D.E.A) is its applicability for the firms that operate under a multiple input-and-output framework. Assessment of efficiency was based on 2 assumptions, namely, fixed and variable efficiency.

Results: The data show that, based on fixed efficiency, the efficiency in the Bushehr, Fars, Kerman, Mazandaran and Yazd provinces is the highest, the average being 80%, which means that the idle capacity is 20% . Based on the variable efficiency. assumption, in Ilam, Chahar Mahal-and-Bakhtiari, Semnan, and Kohgiluyeh Boyerahmad provinces the efficiency is 85% (idle capacity = 20%).

Conclusion: On the whole, the Chaharmahal-Bakhtiyari province is the most efficient in holding Health Services Workshops in Iran. Therefore, other provinces should follow this province as an example when planning to increase their efficiency.

Predictors of self-management behaviors in patients with asthma based on Green's Model of Health Education Planning

M Morowatisharifabad

Background and Aim: Based on WHO reports, there are about 100-150 million people with asthma around the world and the number is increasing. Asthma is a prevalent disease and permanent self-management is needed in order to control the symptoms and maintain the normal action of the lungs and a normal level of activity. The Green's Model of Health Education Planning provides a systematic process for planning, implementation and evaluation of population health promotion programs and is used in a broad range of issues in health promotion, including self-management in asthma. This study was carried out with the aim of determining predictors of self-management behaviors in patients with asthma in Yazd, Iran, based on the above-mentioned model.

Methods and Materials: In this cross-sectional study convenience sampling was employed to recruit 94 outpatients with asthma from among those referring to Shaheed-Sadooghi Clinic in Yazd, Iran. Data were collected using a questionnaire based on the Green's Model constructs, consisting of predisposing, reinforcing, and enabling factors and self-management behaviors. Reliability and validity of the questionnaire were assessed prior to data collection.

Results: The subjects acquired 49.5%, 68.6%, 67.3%, and 61.2 % of the earnable scores for self-management behavior, predisposing factors, reinforcing factors, and enabling factors, respectively. Predisposing, reinforcing, and enabling variables had positive correlations with self-management behaviors (p<0.01) and accounted for 34.6% of the self-management variance. Predisposing factors were the strongest predictor (β = 0.480).

Conclusion: It is concluded that the Green's Model of Health Education Planning can be used in developing countries, such as Iran, as a framework for planning intervention programs in an attempt to improve the self-management behaviors of patients with asthma. Designing and implementing educational programs aiming at promoting self-management behaviors in asthmatic patients with emphasis on predisposing factor enhancement is recommended.

Organic carbon content and potential for formation of disinfection by-products in drinking water of the water distribution system of Tehran, Iran

Mohammad Ali Zazouli

Background and Aim: Natural organic matter (NOMs), measured on the basis of organic carbon, produces disinfection by-products precursors (DBPs) during the chlorination process. Some DBPs are carcinogenic. NOMs are not completely removed by conventional water treatment. As a result, in addition to forming DBPs, they support bacterial regrowth in the water distribution systems and cause unpleasant odor and taste and other problems. The objective of this study was to determine organic carbon concentration and DBPs formation potential in drinking water of the water distribution system in Tehran, Iran.

Methods and Materials: Water sampling was done by standard methods, monthly between August 2006 and Feb 2007, at four points of the drinking water distribution system in Tehran. Quantitative parameters, including pH, EC, UV254 (UV absorbance at a wavelength of 254nm), dissolved organic carbon (DOC), and specific UV absorbance (SUVA) were determined. DOC and UV-254 of the samples were determined using a Total Organic Carbon (TOC) analyzer and a Lambda 25 UV/Vis spectrophotometer, respectively. SUVA (L/mg.m) was calculated as thea ratio of the UV absorbance at 254 nm (1/m) to DOC (mg/ L).

Results: The water content of DOC at the four points of the distribution system was less than 0.7 mg /L. The mean DOC concentration was 0.3±0.14mg/L, ranging between 0.12 and 0.687mg/L, with no monthly variation. The mean SUVA was 1.3±0.7.

Conclusion: It can be concluded that the Tehran water treatment systems cannot eliminate completely natural organic matter. SUVA values show, however, that the system can eliminate the majority of hydrophobic compounds. Therefore, formation of haloacetic acids is more probable than that of trihalomathanes.

Fauna of medically important flies of Muscidae and Fanniidae (Diptera) families in Tehran, Iran

M Khoobdel

Background and Aim: Some medically important species of Muscidae and Fanniidae families are among synanthropic flies and can be seen in human habitats therefore they can be mechanical vectors of different pathogenic microorganisms. Identification and determination of species of these flies is essential for any control program planning. This study was conducted to determine the faunal diversity of Muscidae and Fanniidae flies in Tehran, Iran.

Methods and Materials: This was a cross-sectional descriptive and taxonomic study, conducted in 2 phases, during 1996-97 (pilot study) and 2000-2002 (complementary study) in Tehran and suburbs. Medically important flies were captured and identified. A net-hashing was used to capture adult flies by the direct observing method. To determine the fauna of flies in different habitats, 4 biotopes, including corpse (human, birds, livestock), garbage and decaying organic matter, animal carcasses, and human indoor habitat, were selected. Big hashing nets (95 cm in diameter) were used for capturing adult flies.

Results: A total of 2418 adult flies belonging to 8 families of Muscidae, Fanniidae, Calliphoridae, Sarcophagidae, Tachinidae, Syrphidae, Conopidae, and Anthomyiidae were captured. Among these, 1279 belonged to the Muscidae and Fanniidae families. Four genera and 5 medically important species were identified from two families.

Conclusion: Based on the existing scientific documentation, 2 species of M. stabulans and F. scalaris are reported for the first time from Iran. However, M. stabulans is a common species, the presence of which in Iran seemed probable.

Prevalence of intimate partner violence and views of women on adopting ways to fight against it in Arak city, Iran

M Arab

Background and Aim: Domestic violence against women is a serious public health problem and women adopt different solutions to fight against it. This study was carried out to determine the prevalence of intimate partner violence and views of women
on adopting ways to fight against it in Arak city, Iran, year 2008.

Methods and Materials: In a cross-sectional study in Arak city in 2008, a total of 1037 women were interviewed. The data collected were analysed statistically.

Results: Findings showed that the common types of abuse were emotional (64.6%), verbal (57.1%), financial (32.3%), and physical (26.8%). The women mentioned that the most efficient ways they chose to counteract the abuses were as follows: resuming talking after the settlement of quarrels (93%), keeping silent on the part of one of the partners (81%), and seeking advice from the older members of the family (81%). The considered going into a temporary sulk (51%) and reciprocation (46%) ineffective methods. Correlations were found between violence on the one hand and education, job, addiction of the spouse, income of the spouse, mental disorder of the partner, and number of children on the other hand (p<0.05).

Conclusion: Results of this study show that a large number of women are subjected to different types of violence. It seems that increasing awareness of married women and girls concerning effective counteractive methods can be an effective step in solving this social problem.

Prevalence of intimate partner violence and views of women on adopting ways to fight against it in Arak city, Iran

M Shamsi

Methods and Materials: In a cross-sectional study in Arak city in 2008, a total of 1037 women were interviewed. The data collected were analysed statistically.