effect of air pollution

J Egypt Public Health Assoc

Vol. 84 No. 3 & 4, 2009

Biochemical Changes among Workers Occupationally Exposed to Vibration Khaled F. El-Said*, Ragaa M.El-Gazzar*, Hanan A.Mansour**, Hany K. Abo El-Gheit** *

**

Occupational Hygiene , Occupational Health Department , High Institute of Public Health , Alexandria , Egypt. Abu Queer for Fertilizer and Chemical Industries Company, Alexandria , Egypt.

ABSTRACT With the increasing interaction between workers and mechanical tools, vibration at critical frequencies and acceleration has become an important source of injury. Exposure to occupational vibration has its adverse effects on musculoskeletal, nervous and cardiovascular systems. Certain biochemical changes may occur. Some psychological and physiological disorders were observed. The present study aimed to study biochemical changes among workers occupationally exposed to vibration. The study included a total number of 165 workers (104 exposed to vibration and 61 as a comparison group). Exposed workers were selected from Mousahama El-Behera, Zahran and Lecico companies in Alexandria. They were exposed to Whole – Body Vibration (WBV) (n=77) or Hand – Arm Vibration (HAV) (n=27). Nonexposed workers (n=61) were selected from the same companies. Biochemical changes including hematological changes, coagulation profile, lipid profile, liver and cardiac enzymes, some of trace elements and urinary catecholamine were studied among exposed and control subjects. Significant changes in the levels of tested biochemical parameters were observed among workers exposed to WBV, HAV and control subjects. It can be concluded that workers exposed to occupational vibrations may develop certain occupational diseases, that might be related to the vibration itself. Corresponding Author: Dr. Khaled F. El. Said Department of Occupational Health High Institute of Public Health. Email: [email protected]


Vol. 84 No. 3 & 4, 2009

Key words: biochemical changes, occupational vibration exposure. INTRODUCTION With

the

increasing

interaction

between

workers

and

mechanical tools, vibration at certain frequencies was found to be an important source of injury.(1) Occupational vibration is divided into two types ;general or whole body vibration (WBV), which acts on the body of sitting or standing persons through transporting the vibration from its source to the supporting surfaces at which the person exists, and local vibration or hand-arm vibration (HAV), which is mainly transmitted to hands and arms and sometimes it is called segmental vibration.(2) Workers who are exposed to long-term WBV have been reported to have higher incidence of musculoskeletal, neurologic, circulatory,

digestive,

endocrinological,

biochemical

and

histopathological systems disorders.(1, 3) Hand-arm vibration may lead to vasospastic, neuromuscular or joints disorders. These disorders range from mild and occasional discomfort or inconvenience to severe social and occupational disability.(4) Both types of occupational vibration exposure have their adverse effects on skeletal – muscle, nervous, cardiovascular system, blood biochemistry, and psychological and physiological aspects of the exposed individual. In fact, a wide range of adverse health effects of physical, physiological and psychological nature have been reported.

(4, 5)

Several studies have shown that there

are some biochemical changes due to WBV exposure.(6-8)

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Vibration-induced

Vol. 84 No. 3 & 4, 2009

white

finger

(VWF)

or

Raynaud’s

phenomenon was observed by many investigators to be the most common condition among the operators of hand-held vibrating tools.

(9)

It can cause changes in tendons, muscles, bones and

joints, and collectively they are known as Hand-Arm Vibration Syndrome (HAVS).(9) The present study aimed to study biochemical changes among workers occupationally exposed to vibration. MATERIAL AND METHODS The study included a total number of 165 workers (104 exposed to vibration and 61 as a comparison group). Exposed workers were selected from Mousahama El-Behera, Zahran and Lecico companies in Alexandria. They were exposed either to Whole–Body Vibration (n=77) or Hand–Arm Vibration (n=27). Nonexposed workers (n=61) were selected from the same companies. They had the same demographic characteristics as the exposed group but they were not exposed to vibration. A fasting blood sample (10ml) was collected from each of the examined subjects by venepuncture together with spot urine sample. Standard methods were used to analyze Complete Blood Picture (CBC)(10), Coagulation profile(11), Lipid profile(12), liver and cardiac enzymes(13), some of trace elements(14) and urinary catecholamine.(15) Vibration readings were taken by Schinck vibrotest 60 (Data collector).The WBV measurement and data analysis procedure follows the method of Society of Automotive Engineers

(16, 17);

and

the HAV measurement were done according to the method of ISO 5349 (2001).(18)

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Statistical Analysis The statistical analysis of the results of the present study has been done by using

SPSS program version 10. The Analysis of

Variance (ANOVA) was used for testing the significance when controls and exposed subjects were compared.

RESULTS Results of the studied population are presented to show the effect of occupational vibration on biological parameters among exposed individuals. Table (1) presents the hematological parameters of the examined subjects. Workers exposed to WBV showed low levels of Hb, Ht value, RBCs and PLT count; and high levels of WBCs, MCV, MCH and MCHC relative to non-exposed workers. The differences were insignificant except for RBCs, PLT count and MCH (p < 0.05). On the other hand, workers exposed to HAV showed low levels of all parameters compared to controls except for WBCs, MCH and MCHC which showed higher levels among exposed workers. The differences are statistically insignificant except for Hb, Ht value, RBCs and PLT counts (p < 0.05).

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Vol. 84 No. 3 & 4, 2009

Table (1): Hematological Parameters among Exposed Workers and Control Subjects Measured parameters Hb (a) Ht % (b) RBCs × 106 (cell/mm3) (c) WBCs × 106 (cell/mm3) PLT × 103 (cell/mm3) (d) MCV MCH [e] MCHC (g/100ml packed red cells) * p < 0.05 a: B-C

WBV exposed workers (n=77) Mean±SD [A] 13.16±0.839 43.19±4.171 4.49±0.307

HAV exposed workers (n=27) Mean±SD [B] 12.81±1.06 41.04±3.858 4.43±0.331

control subjects (n=61) Mean±SD [C] 13.41±0.671 44.3±3.095 4.69±0.229

5.129* 7.061* 11.314*

6.29±1.590

6.13±1.929

5.68±1.888

2.069

254.49±59.646

256.59±61.15

291.15±85.899

4.956*

96.82±9.504 29.45±1.861 30.51±2.222

92.56±5.184 28.93±1.072 31.3±1.068

94.46±5.153 28.57±1.024 30.28±1.583

3.746 6.11* 2.871

b: B-C

c: A-C, B-C

d: A-C,

F

B-C

e: A-C

Table (2) shows the coagulation profile of exposed and control subjects. Workers exposed to WBV showed low levels of bleeding time (BT), clotting time (CT) and Fibrogen (Fib) relative to controls. The differences were statistically insignificant except for CT (p < 0.05). On the other hand, the levels of prothrombin time (P.T) were observed to be significantly higher among the exposed workers (p < 0.05). Concerning workers exposed to HAV, the levels of BT, CT and Fib were observed to be lower among exposed

workers

relative

to

control

subjects,

but

with

statistically insignificant differences. On the other hand, workers exposed to HAV showed significant increase in prothrombin time compared to controls (p < 0.05).

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Vol. 84 No. 3 & 4, 2009

Table (2): Coagulation Profile among Exposed Workers and Control Subjects WBV exposed workers (n=77) Mean±SD [A] 133.61±15.352 338.64±89.526 13.72±1.12 236.53±47.773

Measured parameters BT (sec) CT (sec) (a) P.T. (sec) (b) Fib (mg/dl)

* p