Portland Cement Dust Research Articles

Effect of Decomposed-Stone Dust on Properties of Concrete

TThe objective focused on the study of shrinkage behavior of concrete using Decomposed-Stone Dust to replace Portland cement type 1 in the ratio of 10, 15 , and 20 percent by weight of binder as well as designing compressive strength at 280 kg/cm2. Testing the formation time, shrinkage behavior, and compressive strength of concrete was compared with the concrete using Portland cement type 1. The study found that the concrete using Decomposed-Stone Dust was an increased formation period in accordance with the amount of replaced Decomposed-Stone Dust. Autogenous shrinkage, dry shrinkage, and compressive strength of concrete mixed with Decomposed-Stone Dust were less than control concrete. In all mixing ratios, the ratio of 20% replacement of Portland cement dust was the most suitable for this study. The initial formation time was 155 minutes. The final formation period was 305 minutes. The autogenous shrinkage was 312 microns, the dry shrinkage was 699 microns and compressive strength was 286 kg/cm2 respectively at age 28 days.

Occupational Health Exposure and Perceived Effects of Portland Cement Dust Pollution on Cement Factory Workers

The perceived occupational and environmental health challenges arising from the exposure of cement dust pollution on Bua cement factory workers were investigated in this study to establish if there is any significance of cement dust exposure on workers’ health. The study was designed as a cross-sectional type of research that adopted a purposive group based strategy for sampling. 110 cement factory workers with a minimum of two years’ work experience were selected for the study. 90 respondents were randomly selected from a community situated at about 21km away from the factory and used as control. Structured questionnaire was used for data collection and SPSS statistical package was used to analyze the data. Inferential statistics was used to test the hypotheses at p <0.05, ascertain correlation of the variables and authenticate the analysed results. The result revealed that 15 types of ailment were reported among the sampled respondents with factory workers recording higher percentage occurrence of ailments than respondents from the control. Factory workers were more susceptible to the itemized ailments recorded when compared to respondents from control. Significant difference in the prevalence of perceived health ailments between factory workers and control was established. Workers from storage and transportation section were revealed to have higher percentage (77.3%) compliance level on the use of safety gadgets during work hours than workers from other sections. Also, a significant relationship between the perceived health risks associated with cement dust exposure and the health of factory workers was established. The researchers made reasonable recommendations to forestall further health complications that might arise from working on a cement production factory.

Increased incidence of respiratory tract cancers in people living near Portland cement plants in Korea.

Portland cement contains carcinogens such as chromium and free silica, and hence, inhalation of cement dust can cause respiratory tract cancers. The purpose of this study was to determine whether living near a cement plant increases the risk of respiratory tract cancers. The study population consisted of 341,793 people, all of whom lived in administrative districts within 3-km radius of ten cement plants in Korea. The respiratory tract cancer incidence data (International Classification of Diseases, ten revision code C00-C14 and C30-C34) for 2008-2012 were obtained from regional cancer registries. Standardized incidence ratios (SIRs) for each cancer site in the respiratory tract were calculated using an indirect standardization method. Compared with the general Korean population, the incidence of lung and bronchus cancer (C33-C34) was significantly higher in all subjects [SIR 1.15, 95% confidence interval (CI) 1.02-1.29] and especially in the men subjects (SIR 1.47, 95% CI 1.29-1.68) in our study population. In addition, the incidence of larynx cancer in men (SIR 1.64, 95% CI 0.97-2.59) and salivary gland cancer in women (SIR 3.03, 95% CI 0.98-7.07) living near cement plants was marginally increased. These results suggest that environmental exposure to Portland cement dust is a risk factor for respiratory tract cancers.

Effect of Exposure to Portland Cement Dust on the Periodontal Status and on the Outcome of Non-Surgical Periodontal Therapy

Cement dust contains heavy metals like nickel, cobalt, lead and chromium, pollutants hazardous to the biotic environment, with adverse impact for vegetation, human and animal health and ecosystems. To investigate if long term exposure to cement dust can affect the periodontal health and affect the outcome of non-surgical periodontal therapy. A total of sixty subjects were included in this study. Forty patients with chronic periodontitis were grouped into; Group I comprised of 20 patients with chronic periodontitis working in the Portland Cement Company and Group II comprised of 20 patients with chronic periodontitis who does not work in cement factories nor live near any of them. Twenty healthy subjects were included in this study as healthy control group (Group III). Clinical parameters including gingival index (GI), plaque index (PI), pocket depth (PD) and clinical attachment loss (CLA) were scored for all patients before and after periodontal therapy. All patients received non-surgical periodontal therapy together with strict oral hygiene program for one month. Gingival crevicular fluid (GCF) samples were collected from both groups at baseline and one month after periodontal therapy. Real time PCR (RT-PCR) was used to analyze the GCF samples for detection and assessment of the levels of IL-1β and TNFα. The two studied groups responded well to non-surgical periodontal treatment and there was no significant difference between GI and GII (P>0.05). The levels of TNFα was higher in GI than in GII before and after periodontal therapy (P<0.05). The levels of IL-1β did not show any significant difference between the two groups at base line (P>0.05), but represented with a highly significant difference between G1 and GII after periodontal therapy (P<0.001). A significant positive correlation was found between the levels of both IL-1β and TNFα and all the clinical parameters in GI before and after periodontal therapy and in GII before periodontal therapy (P<0.05). It seems that long term exposure to cement dust does not affect the clinical outcome of non-surgical periodontal treatment but it affects the levels of the pro-inflammatory mediators leading to more periodontal tissue destruction.

Effects of occupational dust exposure on the health status of portland cement factory workers

Introduction: Chronic exposure to Portland cement dust has been reported to lead to greater prevalence of various clinical conditions (includes both respiratory and non-respiratory). These conditions are consistently associated with the degree and duration of exposure. Regular use of appropriate personal protective equipment if made available at the work site could protect the cement factory workers from adverse health effects. Objective: To study the morbidity profile of the cement factory workers. Type of Study: Retrospective cohort study. Material and Methods: This study was conducted in the Portland Cement Factory in North Karnataka. Data was collected using predesigned questionnaire by personal interview method and clinical examination. A total of 64 male workers are randomly selected who are working in various departments like crushing, raw/cement mill, rotary kiln and packing department. Equal number of unexposed controls was selected from the area atleast 5 kms from the factory and those who are not exposed to cement dust in the past, who are matched for age, Socio economic status and smoking with the exposed population. Statistical Analysis: Chisquare test for qualitative data and unpaired t test for quantitative data using Epi info. Results: A total of 64 male workers and equal number of matched controls who are not exposed to the cement dust were included in the study. Among exposed maximum of 36% were employed in Crushing department, 25% each in Packing and cement/raw mill. Systolic and Diastolic blood pressure was found to be higher among the exposed, which is statistically highly significant (p Conclusion: Personal protective equipment should be made available at the workplace and educate the personnel to use them. Extensive research is necessary to improve the technical preventive measures that will reduce the risk of occupational health hazards.

Respiratory symptoms and ventilatory function in workers exposed to portland cement dust.

The healthy worker effect and incomplete exposure information have been problems in former studies regarding the association between exposure to Portland cement dust and respiratory effects. We included former workers and made an individual estimation of particle exposure to reduce the selection bias in this controlled cross-sectional study on the effects of cement dust exposure on respiratory symptoms and ventilatory function in long-term exposed Norwegian cement plant workers. A total of 119 workers from the largest cement plant in Norway and 50 workers from a nearby control plant, born 1918 to 1938, performed spirometry and gave information on respiratory symptoms in 1998 and 1999. The prevalence of symptoms and mean pulmonary function indices were similar for exposed workers and controls. There was no dose-response-related increase in symptoms or decrease in lung function indices. The estimated power to detect a true difference between forced expiratory volume in one second (FEV1) in the two groups of 0.3l was 0.90, assuming 95% significance level. The prevalence of chronic obstructive pulmonary disease was 14.3% in the exposed group and 14.0% among the controls. These findings do not support the hypothesis that cement dust exposure has a negative impact on lung function or gives an increase in respiratory symptoms.

Respiratory illnesses and ventilatory function among workers at a cement factory in a rapidly developing country.

Chronic exposure to Portland cement dust has been reported to lead to a greater prevalence of chronic respiratory symptoms and a reduction of ventilatory capacity. The seriousness of pulmonary function impairment and respiratory disease has not been consistently associated with the degree of exposure. Regular use of appropriate personal protective equipment, if available at the worksite, could protect cement workers from adverse respiratory health effects. For a variety of reasons, industrial workers in rapidly developing countries do not adequately protect themselves through personal protective equipment. This study explores the prevalence of chronic respiratory symptoms and ventilatory function among cement workers and the practice of use of personal protective equipment at work. An interviewer-administered questionnaire was used to collect information on sociodemographic characteristics, smoking profile and history of respiratory health among workers at a Portland cement plant (exposed) and workers occupationally unexposed to dust, fumes and gases (unexposed). Pulmonary function was assessed and pulmonary function impairment was calculated for the exposed and the unexposed workers. A higher percentage of the exposed workers reported recurrent and prolonged cough (30%), phlegm (25%), wheeze (8%), dyspnoea (21%), bronchitis (13%), sinusitis (27%), shortness of breath (8%) and bronchial asthma (6%). Among the unexposed, prevalences of these symptoms were 10, 5, 3, 5, 4, 11, 4 and 3%, respectively. Ventilatory function (VC, FVC, FEV(1), FEV(1)/VC, FEV(1)/FVC and PEF) was significantly lower in the exposed workers compared with unexposed workers. These differences could not be explained by age, body mass index (BMI) or pack-years smoked. Ventilatory function impairment, as measured by FEV(1)/FVC, showed that 36% of the exposed workers had some ventilatory function impairment compared with 10% of those unexposed. Certain jobs with greater exposure to cement dust had lower ventilatory function compared with others among the exposed workers. It was concluded that adverse respiratory health effects (increased frequency of respiratory symptoms and decreased ventilatory function) observed among cement workers could not be explained by age, BMI and smoking, and were probably caused by exposure to cement dust.

EFFECTS OF OCCUPATIONAL DUST EXPOSURE ON THE RESPIRATORY HEALTH OF PORTLAND CEMENT WORKERS

The object of this study was to assess the relationship between occupational Portland cement dust exposure and respiratory health. Respiratory symptoms and ventilatory function were studied in a group of 591 male Portland cement workers employed in four cement plants. The prevalence of chronic respiratory symptoms was higher in exposed than in control workers. The exposed group had a significantly lower mean forced vital capacity (FVC), forced expiratory volume at 1 s (FEV1), and forced expiratory flows after exhalation of 50% and 75% of the vital capacity (FEF50, FEF75) than the control group. The data suggest that occupational exposure to Portland cement dust may lead to higher prevalence of chronic respiratory symptoms and the reduction of ventilatory capacity.

Air volume measurement error in pumps with rotameters and high range “constant flow” pumps

The inherent variability of three types of sampling trains commonly used in industrial hygiene field work were compared to that of a “control” sampling train in a laboratory setting. Eight quartets of samples were taken for each sampling train inside a cubic meter aerosol chamber in which Portland cement dust was generated. Side one, used as a control, had each of four sampling cassettes connected to a 2 Lpm critical orifice. Each orifice was connected by manifold to a Little Giant® pump. Side two had four sampling cassettes, each attached to a MSA Model G pump, and the ball setting of each rotameter was adjusted every half hour during sampling. Side three also had four sampling cassettes, each attached to an MSA Model G pump. The rotameters of these pumps were not adjusted during sampling. In the fourth side of the chamber four sampling cassettes were each connected to a DuPont “Constant Flow” Pump, Model P-2500. The variability in concentration among the four samples for each sampling train was calculat...

Air volume measurement error in pumps with rotameters and high range “constant flow” pumps

The inherent variability of three types of sampling trains commonly used in industrial hygiene field work were compared to that of a “control” sampling train in a laboratory setting. Eight quartets of samples were taken for each sampling train inside a cubic meter aerosol chamber in which Portland cement dust was generated. Side one, used as a control, had each of four sampling cassettes connected to a 2 Lpm critical orifice. Each orifice was connected by manifold to a Little Giant® pump. Side two had four sampling cassettes, each attached to a MSA Model G pump, and the ball setting of each rotameter was adjusted every half hour during sampling. Side three also had four sampling cassettes, each attached to an MSA Model G pump. The rotameters of these pumps were not adjusted during sampling. In the fourth side of the chamber four sampling cassettes were each connected to a DuPont “Constant Flow” Pump, Model P-2500. The variability in concentration among the four samples for each sampling train was calculated and compared to the other three sampling trains. The MSA Model G pumps in which the rotameter was adjusted every half hour during sampling had over twice as much variability as the other three sampling trains with a coefficient of variation of 5.80%. The MSA Model G pump with the unchanged rotameter had 2.48%, the DuPont, 2.21%, and the critical orifice, 2.20%.