Lead poisoning among communication radio-repair workers in signal Department Royal Thai Army Samutsakhon Province, Thailand

Abstract

Chronic exposure to low dose of lead can affect to every systems and organs of the human body. Lead poisoning have been found among communication radio-repair workers because lead is routinely used for soldering. The longitudinal study design was used to investigate blood lead level (BLL) and hair lead level (HLL), to determine the association of BLL and HLL with signs and symptoms of lead poisoning among workers and to determine the health risk assessment of lead exposure among workers. There were 66 repair workers in exposed group and 54 office workers in low exposed group at baseline. And, there were 54 workers in exposed group and there were 48 workers in low exposed group at endpoint. General characteristics, Knowledge, Awareness, and PPE used (KAP) of lead exposure, and signs and symptoms were investigated by using a questionnaire. Hair samples were collected to measure excreted lead level. Blood samples were collected to measure lead level and to diagnose anemia, hepatic and kidney functions. Hypertension was also assessed. Descriptive statistic was used to describe all variables. Chi-square test, Independent T-test, and Mann–Whitney U test were used to compare the variables between both groups. Spearman’s correlation was used to determine the correlation between BLL and HLL. Binary logistic regression was used to determine the association of BLL and HLL with signs and symptoms. The results showed the average age, education levels, and study at Signal school of low exposed group were higher than exposed group except for milk drinking (P-value < 0.05). The low median scores of knowledge and PPE used among workers were shown. The highest median BLL and HLL of exposed group were 5.5 µg/dL and 2.9 µg/g, respectively. Low positive correlation between BLL and HLL was also found (P-value < 0.05). The associations between BLL and signs and symptoms including loss of appetite, nausea and vomiting, excessive tiredness or weakness, headache or dizziness, nervous irritability, muscle and joint pain, insomnia, and hypertension were shown (P-value < 0.05). And, there were the associations of nervous irritability and muscle and joint pain with HLL (P-value < 0.05). The adverse health effects for lead exposure can be occurred with a chance of 2.4 time in expose group at baseline and can be occurred with a chance of 2.5 and 3.5 times in low exposed and exposed groups, respectively at endpoint. The findings can be summarized that there were existing adverse effects of low lead levels on the workers. Because of low knowledge and used of PPE among workers, lead poisoning protection program that consists of increasing in KAP of lead exposure should be applied as a guideline.