ASSESSMENT OF RESPIRATORY AND RENAL FUNCTIONS AMONG GAS METAL ARC WELDERS AND THEIR RELATIONS WITH CHROMIUM EXPOSURE - PDF

Please download to get full document.

View again

of 15
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
Information Report
Category:

Genealogy

Published:

Views: 0 | Pages: 15

Extension: PDF | Download: 0

Share
Related documents
Description
Egyptian Journal of Occupational Medicine, 2007; 31 (1) : Resp. and Renal Functions Among Metal Arc Welders 107 ASSESSMENT OF RESPIRATORY AND RENAL FUNCTIONS AMONG GAS METAL ARC WELDERS AND THEIR
Transcript
Egyptian Journal of Occupational Medicine, 2007; 31 (1) : Resp. and Renal Functions Among Metal Arc Welders 107 ASSESSMENT OF RESPIRATORY AND RENAL FUNCTIONS AMONG GAS METAL ARC WELDERS AND THEIR RELATIONS WITH CHROMIUM EXPOSURE By Helal SF (1), Arafaa AM (2), and Afify M (3) FROM Industrial Medicine and Occupational Diseases department (1), NECTR (2), NRCD Biochemistry Department (3) Faculty of Medicine-Cairo University ABSTRACT Background: Welding is the most common way of permanently joining metal parts. Welders use many types of welding equipment set up in a variety of positions. Arc welding is the most common type. Welding, soldering, and brazing workers often are exposed to a number of hazards, including the intense light created by the arc, poisonous fumes, and very hot materials.objective: The aim of the present study was to investigate some of the health hazards among gas metal arc welders with special emphasis on renal and lung examination and to monitor the level of chromium in blood and urine, and studying its relation with the renal condition. Our aim was also to detect early renal affection by measuring of B 2 microglobulin in urine. Subjects and methodology: This study was conducted in three welding shops in El Manial, and El Maadi, in Cairo. The study was accomplished during the months of October and November, 2006.The studied group comprised 18 workers in the metal arc welding shops. They were adult men aged between years (26.5 ±7.8), working on the basis of 12 hours/day with one day off per week. None of the workers used any protective equipment during working hours. A referent group of 20 males matched for age that ranged from yrs., (26.2±6.38), sex, socio-economic status, smoking 107 108 Helal SF. et. al habits, selected from relatives of the Kasr El Eini hospital patients, were also enrolled in our study. The following investigations were performed after taking individual consent: (A) All workers were interviewed using a special questionnaire including occupational history.(b) Ventilatory function tests were done measuring FVC, SVC, FEV1%, FEV1/FVC, and PEF. (C) Beta2 Microglobulin in urine.(d) Blood and urine chromium levels.(e) Urea and creatinine and fasting serum sugar level. All investigations were done at The Biochemistry department at The National Research Centre, Dokki. Results: showed a statistically significant difference between the exposed and the control groups as regards spirometric evaluation of FEV1/FVC, PEF%, and MEF 25-75%. Our results revealed also a statistically significant difference between the exposed and the control groups as regards the level of chromium in blood and urine and the level of B2 microglobulin in urine. There is also a statistically significant difference between both groups as regards the blood level of urea and creatinine, but there is no statistically significant difference between both groups as regards the level of fasting blood sugar. Our research showed a statistically significant difference between the exposed and the control groups as regards the occurance of metal fume fever. Among the exposed group there was no statistically significant difference between smokers and non smokers as regards the level of chromium in blood and urine, the level of B 2 microglobulin in urine and there was no statistically significant difference between both groups as regards renal function tests and the level of fasting blood sugar level, but there was a statistically significant difference between both groups as regards FVC% and SVC%. Our results showed that there was no statistically significant correlation between the duration of exposure to chromium in welders and all investigations done, but there was a statistically significant correlation between the level of chromium in blood and spirometric parameters and the levels of chromium in urine, B 2 microglobulin in urine, urea, and creatinine. Recommendations: From the present study we recommend environmental monitoring in different areas in the welding shops to ensure that permissible levels of different hazardous agents are not exceeded. Pre-employment and periodic medical examinations must be performed to exclude those susceptible to lung and renal diseases. Personal protective clothes e.g. gloves and respiratory protective equipment should be used in welders. Health education programs of workers about hazards of exposure to harmful agents and proper measures for protection is essential and this includes training programs to raise awareness among welders. Effective local exhaust ventilation to remove hazardous gases and fumes is essential. Finally, urinary or blood chromium can be used as indicators of recent chromium exposure among welders. Key words: Metal arc welders- Chromium- B2 microglobulin- MFF. Resp. and Renal Functions Among Metal Arc Welders 109 Introduction Gas Metal-Arc Welding (GMAW), also called Metal Inert Gas (MIG) welding, shields the welding zone with an external gas such as argon, helium, carbon dioxide, or gas mixtures. Deoxidizers present in the electrode can completely prevent oxidation in the weld puddle, making multiple weld layers possible at the joint. GMAW is a relatively simple, versatile, and economical welding apparatus to use. This is due to the factor of two times welding productivity over Shielded Metal Arc Welding (SMAW) processes that is one of the oldest, simplest, and most versatile arc welding processes. The arc is generated by touching the tip of a coated electrode to the workpiece and withdrawing it quickly to an appropriate distance to maintain the arc. In addition, the temperatures involved in GMAW are relatively low and are therefore suitable for thin sheet and sections less than 1/4 inch. GMAW may be easily automated, and lends itself readily to robotic methods. It has virtually replaced SMAW in present-day welding operations in manufacturing plants (Lyndon 2004 ). In welding or cutting, the intense heat of the arc or flame vaporizes the base metal and/or the electrode coating. This vaporized metal condenses into tiny particles called fumes. These fume particles can be inhaled. Chromium fume is created by welding or cutting on stainless steel or metals that are coated with a chromium material. Welding on stainless steel without adequate control measures can lead to exposure at least several times above the legal exposure limit. oco/ocos226.htm Among the short term effects of welders exposure is metal fume fever, symptoms of which occur 4-12 hours after exposure and include chills, fever, muscle ache, chest soreness, coughing, wheezing, fatigue, nausea, and a metallic taste. Welding fumes can irritate the eyes, nose, chest and respiratory tract and cause coughing, wheezing shortness of breath, bronchitis, pulmonary edema, and pneumonitis. Gastro-intestinal effects such as nausea, appetite loss, vomiting, cramps, and slow digestion also have been associated with welding fumes. Ultra-violet radiation given off by welding reacts with oxygen and nitrogen in the air to form ozone and nitrogen oxides, which are deadly at high doses, irritate the nose and throat, and cause serious lung diseases. Long term effects include increased risk of lung cancer and possible larynx and urinary tract cancer as welding fumes, contain cancer causing agents such as cadmi- 110 Helal SF. et. al um, nickel, chromium, beryllium, and arsenic. Welders also may have chronic respiratory problems. Other health problems that appear to be related to welders include heart diseases, skin diseases, hearing loss, and chronic gastritis. Studies have shown that welders, especially those who work with stainless steel, have poorer sperm quality than men in other works. Other studies reported neurodegenerative diseases that affect mental and physical ability (Vicki 2003). Glomerular injury has been noted in chromium workers, in chrome platers, and in stainless steel welders. The predominant renal injury is tubular. Low doses chromium exposure typically results only in transient renal effects (Powers et al., 1986). Increased urinary levels of B2 microglobulin are found in people with kidney damage caused by high exposure to the heavy metals. Periodic testing of workers exposed to these metals helps to detect beginning kidney damage (Henry 1996). Aim of the work The aim of the present study was: (1) To investigate some of the health hazards among gas metal arc welders with special emphasis on renal and lung examination. (2) To monitor the level of chromium in blood and urine, and studying its relation with the renal condition.(3) Assessment of B2 microglobulin in urine. Subjects and methods This study was conducted in three welding shops in El Manial, and El Maadi, in Cairo. The study was accomplished during the months of October and November The studied group comprised 18 workers in the metal arc welding shops. They were adult men aged between years (26.5 ±7.8), working on the basis of 12 hours/day with one day off per week. None of the workers used any protective equipment during working hours. A referent group of 20 males matched for age ( that ranged from yrs., 26.2±6.38), sex, socio-economic status, smoking habits selected from relatives of the Kasr El Eini hospital patients, were also enrolled in our study. The following investigations were performed after taking individual consent: (A) All workers were interviewed using a special questionnaire including occupational history ; and full clinical examination was performed. (B) Ventilatory function tests were done using portable spirometer connected to a portable computer using the soft ware ZAN program, measuring FVC (Forced Resp. and Renal Functions Among Metal Arc Welders 111 vital capacity), SVC (Slow vital capacity), FEV1% (Forced expiratory volume in the 1st second), FEV1/FVC %, and PEF (Peak expiratory flow). (C) Beta2 Microglobulin in urine. Random urine sample was used, volume between 1-10 ml, taken in plastic urine container ( not acidified). Patients were instructed to empty their bladders then drink a large glass of water and then we collected the urine samples from them within one hour at Kasr El-Eini (Industrial and occupational department). The samples were kept in the refrigerator till transferred to the lab. Significant loss of B2 microglobulin activity may occur in acidic urine (ph or = 6), So ph of urine was adjusted to be between ( 6-8) with 1 mol/l sodium hydroxide. Analysis of B2 microglobulin in urine was done using immunochemiluminometric assay (ICMA). Normal range is (0-160) ug/l ( Henne et al., 1997). (D) Blood and urine chromium levels.(e) Urea and creatinine and fasting serum sugar level. Normal blood chromium concentrations are in the range of 10 µg/l to 30 µg/ L Chromium rapidly clears from the blood, and measurements relate only to recent exposure (Goyer and Clarkson, 2001). Normal urinary chromium values are typically less than 10 µg/g creatinine (Goyer and Clarkson, 2001). Blood sample collection From each subject, 10 cc of blood were taken through a vein puncture using a dry plastic disposable syringe under complete aseptic condition. Three cubic centimeters of blood were taken into a clean tube containing anticoagulant for determination of chromium level in blood. The remaining 7 cc of blood were kept in a tube and allowed to clot then centrifuged for separation of the serum for determination of the following biochemical parameters using Hitashi (911) auto analyzer: i- Kidney function test as urea and creatinine, ii- Random serum sugar level. All Samples were transported to the laboratory on the same day within two hours to be analyzed. Urine sample collection: A urine sample was collected from each subject, in a sterile container. All subjects washed their hands with soap and water prior to sample collection to avoid contamination. Determination of chromium in blood and urine: The samples for blood chromium level were prepared by dilution of 0.5 ml of blood with 2 ml deionized water. The sam- 112 Helal SF. et. al ples of urine were prepared by dilution of 1 ml of urine with 1ml of deionized water. The chromium in blood and urine were measured by graphite furnace atomic absorption spectrophotometer (Perkin-Elmer model 5100 PC, Norwalk, CT). 1-Sample preparation: Three per cent butan-1-ol was added to samples and standards to match the carbon content with the aim of ensuring that the ionization efficiency of elements such as chromium is the same in all solution. TAMA 0.1% chemicals (Kwasaki city, Japan) supercleaning, (high purity surfactant), was added to maintain a stable emulsion within the diluted sample. HNO3 0.05% was added to ensure that the trace elements are maintained in solution and to aid wash out of these elements between samples; the acid concentration was kept to a minimum, otherwise cellular component in blood sample in particular will aggregate. 2-Calibration solution preparation: External calibrator for chromium was prepared by serial dilution of parent stock (1000 µg/ml) using the diluents as those used to dilute and prepare the sample. 3-Optimization of technique: For reading concentration of both sample and standard (calibrator), first it was important to choose proper wave length, lamp current band pass optimization. 4-Calculation of the results: By plotting standard curve, the reading of absorbance of sample and calibrator was plotted on semilog curve, the concentration of Cr in sample was interpreted from this standard curve. All investigations were done at The Biochemistry department at The National Research Centre, Dokki. Results and Discussion Chromium is a metal which exists in several different forms: divalent, trivalent, and hexavalent. Workers in many different occupations are exposed to hexavalent chromium. Occupational exposures to hexavalent chromium occur mainly among workers who: a) handle dry chromatecontaining pigments; b) spray chromatecontaining paints and coatings; c) operate chrome plating baths; and d) weld or cut chromium-containing metals such as stainless steel (Cohen and Costa 1998). Our results showed a statistically significant difference between the exposed and the control groups as regards the spirometric parameters indicating air-ways obstruction such as FEV1/FVC%, PEF%, and MEF 25-75% as shown in (table1), and these results are in accordance with Resp. and Renal Functions Among Metal Arc Welders 113 (Frantzen 1998) who reported that the primary target organ for subchronic and chronic chromium toxicity is the respiratory system as evidenced by various signs and symptoms ranging from irritation of the respiratory tract, obstructive air ways to perforation of nasal septum. We demonstrated also in our work that there was a statistically significant difference between the exposed and the control groups as regards the levels of chromium in blood and urine even though these levels did not exceed the normal range, but were still higher in the exposed than in the control group. There are no routine medical tests to measure the amount of hexavalent chromium that has been absorbed into the body. Excreted chromium can be measured in urine. However, this test is only useful for measuring recent exposure to stainless steel welding fumes. In most situations, air monitoring gives the best measure of worker exposure (ATSDR, 2000). Huvinen and his colleagues (1996) conducted a cross sectional study to determine whether occupational exposure to hexavalent chromium caused respiratory diseases, decrease in pulmonary functions, or signs of pneumoconiosis in stainless steel production workers and they found that with high level of blood and urine chromium levels there was also a great insult on the pulmonary functions and these results are consistent with our results. Since uncontrolled diabetes mellitus may lead to proteinuria, we compared between the exposed and control groups as regards the level of fasting blood sugar, and we found no statistically significant difference between both groups as regards the blood sugar level, but we found a statistically significant difference between both groups as regards the level of B2 microglobulin. These results can be explained by the fact that glomerular injury has been noted in chromium workers, but the predominant renal injury is tubular, with low doses acting specifically on the proximal convoluted tubules. Low-dose, chronic chromium exposure typically results only in transient renal effects. Elevated urinary B2-microglobulin levels (an indicator of renal tubular damage) have been found in chrome platers, and higher levels have generally been observed in younger persons exposed to higher Cr (VI) concentrations (Powers et al., 1986). Liu and his colleagues (1993) found a statistically significantly higher urinary B2-microglobulin level in hard-chrome electroplaters exposed to mg chromium/m3 for a mean of 5.8 years and these results are in accordance with our results. We also 114 Helal SF. et. al showed a statistically significant difference between the exposed and the control groups as regards urea and creatinine levels. Verschoor and his colleagues (1988) who compared renal function test results in chrome platers and construction workers revealed that the chrome platers had significantly (p 0.001) higher levels of urinary chromium but there was no differences in blood urea, creatinine, or urinary B2-microglobulin. These results do not go with our results and this may be due to the fact that results of the exposed and the control groups in our work which are statistically different are still in the normal range. Table (1) Comparison between the exposed and control groups as regards different investigations:- The studied Exposed group Control group groups N:18 N:20 t test P value Parameters Mean ±SD Mean ±SD and normal values FVC% of the predicted 78.5 ± ± SVC% of the predicted ± ± FEV1/FVC ± ± PEF% of the predicted 61.6 ± ± MEF 25/75% of the predicted 61.1 ± ± Chromium in blood (Up to 30 ug/l) 13.9 ± ± Chromium in urine ( 10 ug/g creatinine) 8.6 ± ± B2 microglobulin in urine (0-160 ug/l) ± ± Urea (10-20 mg/dl) 20.9 ± ± Creatinine ( mg/dl) 1.02 ± ± Fasting blood sugar ( mg/dl) ± ± Despite the fact that there is no statistically significant difference as regards smoking habit between exposed and controls group (p 0.05) (table 2), table (4) shows that the mean values of FVC% of pred., SVC% of pred., and FEV1/FVC among the exposed group are statistically significantly lower than those of the controls (p 0.05). Our study is more or less in consistent with the results of (Shirakawa and Morimoto 1996); the irritant effect of chromium compounds can explain this pulmonary dysfunction. Resp. and Renal Functions Among Metal Arc Welders 115 Table (2) Smoking habit among the examined groups:- Studied Smokers Non smokers Total group N % N % Exposed Control Total X P value Our study demonstrated a statistically significant difference between the exposed and the control groups as regards the occurance of metal fume fever as shown in (table 3). The Agency for Toxic Substances and Disease Registry (ATSDR, 2005) reported that inhaling large amounts of metal or metal oxides (as zinc dust or fumes from smelting or from welding as chromium oxides) can cause a specific short-term disease called metal fume fever, which is generally reversible once exposure to these fumes ceases. The effects of inhalation exposure to chromium compounds vary somewhat with the chemical form of the chromium compound, but the majority of the effects seen will occur within the respiratory tract. The term metal-fume fever describes an acute industrial illness characterized by a variety of symptoms, including fever, chills, dyspnea, muscle soreness, nausea and fatigue, which occur in workers following the inhalation of finely dispersed particulate matter formed when certain metals are volatilized. The oxides of a number of metals, including zinc and chromium, can cause this acute, reve
Recommended
View more...
We Need Your Support
Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

Thanks to everyone for your continued support.

No, Thanks
SAVE OUR EARTH

We need your sign to support Project to invent "SMART AND CONTROLLABLE REFLECTIVE BALLOONS" to cover the Sun and Save Our Earth.

More details...

Sign Now!

We are very appreciated for your Prompt Action!

x