Reducing lead exposure by surveillance system: the Taiwan experience

Association between Blood Lead Level and Blood Pressure in Aborigines and Others in Central Taiwan

To investigate the relationship between the blood lead level (BLL) and blood pressure among aborigines and non-aborigines in central Taiwan, a community-based survey that included demographic data, medical history, and blood chemistry analyses was conducted among 2,565 adults during an annual health examination. BLLs were analyzed using a graphite furnace atomic absorption spectrometer (AAS). There was a dose response among the non-aborigines (high BLL odds ratio = 2.97, compared with low BLL) but not among aborigines. Based on multiple linear regression models, BLLs were positively correlated with both systolic (an increase of 0.85 mm Hg/microg/dL) and diastolic (an increase of 0.48 mm Hg/microg/dL) blood pressures after adjusting for age, gender, ethnic group, alcohol consumption, and body mass index. BLLs were higher among aborigines than non-aborigines and were significantly correlated with blood pressure, particularly systolic pressure. The association should be considered causal.

Occupational neurotoxic diseases in taiwan

Occupational neurotoxic diseases have become increasingly common in Taiwan due to industrialization. Over the past 40 years, Taiwan has transformed from an agricultural society to an industrial society. The most common neurotoxic diseases also changed from organophosphate poisoning to heavy metal intoxication, and then to organic solvent and semiconductor agent poisoning. The nervous system is particularly vulnerable to toxic agents because of its high metabolic rate. Neurological manifestations may be transient or permanent, and may range from cognitive dysfunction, cerebellar ataxia, Parkinsonism, sensorimotor neuropathy and autonomic dysfunction to neuromuscular junction disorders. This study attempts to provide a review of the major outbreaks of occupational neurotoxins from 1968 to 2012. A total of 16 occupational neurotoxins, including organophosphates, toxic gases, heavy metals, organic solvents, and other toxic chemicals, were reviewed. Peer-reviewed articles related to the electrophysiology, neuroimaging, treatment and long-term follow up of these neurotoxic diseases were also obtained. The heavy metals involved consisted of lead, manganese, organic tin, mercury, arsenic, and thallium. The organic solvents included n-hexane, toluene, mixed solvents and carbon disulfide. Toxic gases such as carbon monoxide, and hydrogen sulfide were also included, along with toxic chemicals including polychlorinated biphenyls, tetramethylammonium hydroxide, organophosphates, and dimethylamine borane. In addition we attempted to correlate these events to the timeline of industrial development in Taiwan. By researching this topic, the hope is that it may help other developing countries to improve industrial hygiene and promote occupational safety and health care during the process of industrialization.

A follow-up comparison of blood lead levels between foreign and native workers of battery manufacturing in Taiwan

Foreign workers employed in industries in Taiwan have been found at elevated risk of injuries. Less well known is whether the elevated risk persists in chemical exposure such as lead exposure at battery manufacturing. A cohort of 70 Thai workers and 55 native workers employed at a battery plant were followed up, after an education of job safety, from 2000 until 2002. This study compared the change of blood lead levels (BLLs) between these two groups of workers. With informed consent, BLLs were measured annually for participants and compared. The average baseline BLLs were approximately at similarly high levels between Thai workers and native workers with means +/- standard deviations of 36.9 +/- 16.4 and 36.2 +/- 12.4 microg/dl, respectively (p = 0.79). At the end of 2002, the average concentration was higher in Thai workers than in native workers. Using mixed models, Thai workers had an average of 5.95 microg/dl increase in BLLs over native workers during the 3-year study. Further measurements revealed that the average BLL for workers in the assembly department was 3.57 +/- 1.83 microg/dl in excess, compared with workers in the plate engineering department. Thai workers were more likely to drink alcohol but less likely to wear gloves at work and wash hands before meals. The BLL disparities between Thai workers and native workers can partly be explained by differences in risk-taking behaviors. Higher BLLs in Thai workers suggest the need of language appropriate health education to improve their personal hygiene. Workplace smoking ceasing program may be needed both in Thai and native workers.

Neurobehavioral changes in Taiwanese lead-exposed workers

OBJECTIVE

The dysfunction of the central nervous system (CNS) caused by lead exposure was evaluated.

METHODS

Workers who have been exposed to lead for at least 3 years and have been informed of having elevated blood lead levels (BLLs) were recruited. According to their current BLLs, 33 and 28 males were assigned to the medium (40-80 microg/dL) and low (<40 microg/dL) BLLs groups, respectively. Sixty-two nonexposed healthy men served as the control group. Their neurobehaviors were examined by a computerized evaluation system.

RESULTS

Significantly impaired neurobehavioral functions were shown in the medium BLLs group, which included slow performance of psychomotor tasks, impaired processing of visual-spatial information, reduced memory and learning functions, low performance accuracy, slow execution of responses, and poor attentional control.

CONCLUSIONS

Subtle CNS dysfunction could be detected from lead-exposed workers who have no obvious neurologic and cognitive deficits.

Relationship between blood lead concentrations and learning achievement among primary school children in Taiwan

Over the past 20 years lead has been proven to exert an influence on the intelligence of children. Especially for children exposed to environmental lead, average blood lead was often lower than the officially recognized intoxication level. Because Kaohsiung is an industrial area in Taiwan and lead exposure is an important environmental issue, we attempted to ascertain the extent to which environmental lead influences the achievement of primary school children. We randomly selected 934 children from 32 primary schools in 11 districts of Kaohsiung City. Blood lead levels of the children were checked, and they were administered a questionnaire about their family information. Scores of several courses were used in this study on the relationship between a child's blood lead and his or her academic performance (Ranking with his or her classmates), including Chinese (reading and writing short Chinese articles), Mathematics, History and Society, and Natural Science. Multiple regression models were done with adjustments for the confounding effects of their parents' socioeconomic levels. The mean (SD) of 934 blood lead level was 5.50 (1.86) microg/dL. Spearman's coefficient showed that class rankings in Chinese, Mathematics, Natural Science, and History and Society were all strongly associated with blood lead levels (P<0.01). The multiple regression models revealed that blood lead level exerts a stronger influence on children's language ability (Chinese) than on their ability to calculate (Mathematics). Our results suggest that environmental lead exposure adversely affects a child's academic achievement, making a direct link between exposure to lead and academic attainment.

Elevated blood lead levels among adults in Massachusetts, 1991-1995

OBJECTIVE

Lead poisoning, the oldest recognized occupational disease, remains a danger for children and adults. Data collected for 664 cases reported to the Massachusetts Occupational Lead Registry in 1991-1995 were summarized in a 1998 state report. Here, the authors present some of the key findings from that report for a wider audience.

METHODS

The authors summarize key findings of the 1998 state report.

FINDINGS

Construction workers, in particular licensed deleaders and house painters, accounted for almost 70% of occupational cases involving blood lead levels > or = 40 micrograms of lead per deciliter (mcg/dl) of blood. Among 100 workers with the highest blood lead levels (> or = 60 mcg/dl), 29% were house painters. Hispanic workers were over-represented in the Registry. A small proportion of cases were non-occupational, typically associated with recreational use of firing ranges or do-it-yourself home renovations.

CONCLUSION

Lead poisoning is a preventable disease, yet these data indicate that additional prevention efforts are warranted.