Trends in blood lead levels in Christchurch (NZ) and environs 1978-85.

Blood lead levels have been monitored since 1974 and have shown a significant decrease (p less than 0.001) from 1978 to 1985 in 2830 subjects from Christchurch and environs. From a baseline in August 1978-81 to August 1985 blood lead levels in a population which had no relevant exposure to lead other than that from the general environment have fallen in adult males and females (greater than 17 years) by 42%, and in school and pre-school children greater than 9 months by 44% and 46% respectively. Reduction of blood lead has accelerated during the last three years. This can be linked to changes in dietary intake and clean up of lead in domestic and industrial environments. Over this decade the lead content of petrol (0.84 g/l) and petrol sales have remained unchanged.

Teamwork can improve the health of lead process workers.

A team working co-operatively to improve the health of lead workers has evolved over the last 10 years. We have monitored 704 employees for red cell lead (4800 samples) from a factory since 1974. In 1975, 32 employees, one-third of the workforce were suspended at a red cell lead level of greater than 10.7 mumol/l. Since 1980 no-one has been suspended at the current lower level of 7.7 mumol/l. By June 1984 the red cell lead mean for all process areas is less than 4.5 mumol/l (average 3.6 mumol/l). In 1984 the usual red cell lead range for local non-industrially exposed adult males is 1.23 SD 0.65 mumol/l. The value of cumulative reporting and contributory factors in reducing the blood levels are discussed.

Industrial lead exposure: a review of blood lead levels in South Island industries, 1974-83.

Relative risks of increased lead absorption found in 31 occupations were investigated. Serial red cell lead measurements on 1319 males and 186 females provided a mean and range for each occupational type. The magnitude of the mean and percentage of raised levels identified the degree of occupational risk. The mean red cell lead for 50% of employees was within the regional usual range for those not occupationally exposed. In 77% the mean red cell lead was less than 4.1 mumol/l. Of the remainder, 4% had levels greater than 5.7 mumol/l and 1% had levels greater than 7.7 mumol/l. Our findings have been used to manage local chronic and acute lead problems.

Diabetes mellitus in a Christchurch working population.

Using criteria recommended by the World Health Organisation, prevalence rates for diabetes mellitus have been determined in a Christchurch working population of adults aged 15-65 years. Ninety-three percent of 1047 workers employed by a large industrial group were screened for diabetes mellitus using 75 G oral glucose tolerance tests. Three point one percent of the survey group were diabetic--1.55% were known to have diabetes and a further 1.55% were new cases. In addition, 0.31% were considered to have gestational diabetes mellitus. Blood glucose elevations not diagnostic for diabetes mellitus were present in another 0.93%. By applying the criteria of the National Diabetes Data Group, slightly different prevalence rates were found--3.0% for diabetes mellitus and 1.14% for impaired glucose tolerance.