The alpha spectrometry measurements of specific activity of 238Pu and 239Pu in urine from bioassay examinations of 1,013 workers employed at the radiochemical and plutonium production facilities of the Mayak Production Association and in autopsy specimens of lung, liver, and skeleton from 85 former nuclear workers who died between 1974-2009, are summarized.The accumulation fraction of 238Pu in the body and excreta has not changed with time in workers involved in production of weapons-grade plutonium production (e.g., the plutonium production facility and the former radiochemical facility). The accumulation fraction of 238Pu in individuals exposed to plutonium isotopes at the newer Spent Nuclear Fuel Reprocessing Plant ranged from 0.13% up to 27.5% based on the autopsy data. No statistically significant differences between 238Pu and 239Pu in distribution by the main organs of plutonium deposition were found in the Mayak workers. Based on the bioassay data,the fraction of 238Pu activity in urine is on average 38-69% of the total activity of 238Pu and 239Pu, which correlates with the isotopic composition in workplace air sampled at the Spent Nuclear Fuel Reprocessing Plant. In view of the higher specific activity of 238Pu, the contribution of 238Pu to the total internal dose, particularly in the skeleton and liver, might be expected to continue to increase, and continued surveillance is recommended.
The prevalence of posterior subcapsular cataracts in young patients receiving inhaled glucocorticoids for treatment of chronic asthma is unknown. In a cross-sectional study, slit-lamp examinations were done on 95 consecutive young patients who were taking inhaled beclomethasone or budesonide. No posterior subcapsular cataracts were found. The median age of the patients was 13.8 (range 5.8-24.8). The median dose of inhaled beclomethasone or budesonide was 750 micrograms/day (range 300-2000), or 12.9 micrograms/kg per day (range 7.5-34.2). The median duration of treatment was 5 years (range 1-15). 77% of the patients had not used oral glucocorticoids in the year preceding the examination. This study suggests that routine screening for posterior subcapsular cataracts in this patient population is not warranted.
Comment In: Lancet. 1993 Nov 20;342(8882):1306-77901619
Americium-241 (²4¹Am) is the second most significant radiation hazard after ²³?Pu at some of the Mayak Production Association facilities. This study summarizes current data on the accumulation, distribution, and excretion of americium compared with plutonium in different organs from former Mayak PA workers. Americium and plutonium were measured in autopsy and bioassay samples and correlated with the presence or absence of chronic disease and with biological transportability of the aerosols encountered at different workplaces. The relative accumulation of ²4¹Am was found to be increasing in the workers over time. This is likely from ²4¹Pu that increases with time in reprocessed fuel and from the increased concentrations of ²4¹Am and ²4¹Pu in inhaled alpha-active aerosols. While differences were observed in lung retention with exposures to different industrial compounds with different transportabilities (i.e., dioxide and nitrates), there were no significant differences in lung retention between americium and plutonium within each transportability group. In the non-pulmonary organs, the highest ratios of ²4¹Am/²4¹Am + SPu were observed in the skeleton. The relative ratios of americium in the skeleton versus liver were significantly greater than for plutonium. The relative amounts of americium and plutonium found in the skeleton compared with the liver were even greater in workers with documented chronic liver diseases. Excretion rates of ²4¹Am in ‘‘healthy’’ workers were estimated using bioassay and autopsy data. The data suggest that impaired liver function leads to reduced hepatic ²4¹Am retention, leading to increased ²4¹Am excretion.
Sulfur dioxide absorbs ultraviolet light in the region of the spectrum which is most active in forming vitamin D on the skin. Sulfate particles reflect light at this wavelength. High concentrations of these pollutants (acid haze) may lead to vitamin D deficiencies in exposed populations. Epidemiologic and laboratory evidence suggests that vitamin D plays a role in reducing risk of colon and breast cancer. We examined the association between sulfur dioxide and ultraviolet-light-blocking aerosols in 20 Canadian cities, and age-adjusted breast and colon cancer mortality rates in the census divisions encompassing these cities. Statistically significant positive associations were found between these two measures of air pollution and age-adjusted mortality rates for colon cancer in women (multiple r = +.74, p = 0.003), and men (multiple r = +.61, p = 0.03), and breast cancer in women (multiple r = +.69, p = 0.007). Mortality rates for all other reported cancer sites were also examined, and no statistically significant positive associations were found consistently in both sexes. The ecological nature of this study is emphasized, and the possibility that an indirect association could explain these findings is discussed.
Overall 50 children suffering from infectious-allergic bronchial asthma who live in ecologically contrasting regions were examined. Those children residing in unfavourable, in terms of ecological conditions, regions demonstrated diminution of the peripheral blood T-lymphocytes together with a decrease in their functional activity as well as in the activity of interleukin 2. It is in this group of children that immunomodulating effect of thymalin is less apparent. It is suggested that the relevant immune correction in such cases might be achieved through repeated courses of treatment with immunomodulating agents and rehabilitation of patients in favourable ecological conditions together with prescribing of other immunostimulators of selective action in respect of the T-link of the immunity system.
BACKGROUND: Dry powder inhalers (DPI) have in recent years become a common mode for administration of inhaled corticosteroids for preventive therapy of asthma. Inhaled steroids delivered by DPI achieve increased lung deposition compared with pressurized metered-dose inhalers (pMDI), which is associated with increased therapeutic effect. This may be associated with increased systemic absorption. OBJECTIVE: The purpose of this study was to evaluate the prevalence of adrenal suppression in children using low-dose budesonide given by DPI, as compared with pMDI attached to a large-volume spacer device (pMDI + spacer). METHODS: In an open-labeled crossover study, 15 asthmatic children aged 5 to 15 years received 200 microg of inhaled budesonide twice daily by DPI (Turbuhaler, Astra, Draco AB, Lund, Sweden) and by pMDI + spacer, 1 month each, in a randomized order. Twenty-four-hour urine collections were performed at baseline and at the end of each of the 2 months of the study period, and urinary cortisol and creatinine were measured. RESULTS: Baseline urinary cortisol:creatinine was 0.038 +/- 0.012 microg/mg, similar in both groups. After 1 month of DPI therapy, urinary cortisol:creatinine was reduced by 27 +/- 16% to 0.028 +/- 0.012 microg/mg (P = 0.018). Urinary cortisol:creatinine after 1 month of pMDI + spacer therapy was similar to baseline 0.037 +/- 0.019 microg/mg (P = 0.78). CONCLUSIONS: Treatment of asthmatic children with budesonide 400 microg daily given via a DPI for 1 month was associated with hypothalamic-pituitary-adrenal axis suppression. This effect was not observed with the same dose of budesonide administered via pMDI + spacer. This indicates that systemic absorption might be reduced with pMDI + spacer therapy.
Comment In: Ann Allergy Asthma Immunol. 2002 Dec;89(6):537-912487216
Annually, large tracts of forest in eastern Canada are sprayed aerially with insecticides (fenitrothion, aminocarb) in attempts to control an epidemic infestation by an indigenous forest pest, the spruce budworm (Choristoneura fumiferana, Clemens). The massive size of the spraying programs, the anecdotal reports of human exposure, and the potential for hazard to human health have led one province. New Brunswick, to initiate and fund specific environmental and laboratory studies which will provide adequate data upon which the government can base realistic legislation to protect both the forests and the population. These studies have included some unique field analyses of aerial spray drift conducted by a research group from the National Research Council; comparative subchronic studies in rats of fenitrothion and a new formulation; a nose-only inhalation study of this formulation in rats; field testing of the formulation for drift characteristics. Ongoing research involves the subchronic testing of the emulsifying agents being used routinely in the new formulation and studies of a low-drift additive which will stabilize the particle size of the spray. On the basis of the results to date, the government has been able to modify spraying techniques and to establish realistic buffer zones around human habitation.
OBJECTIVE: Primary prophylaxis against Pneumocystis carinii pneumonia (PCP) for patients with HIV infection has been recommended by the Centers for Disease Control and Prevention. We evaluated alternatives to routine primary PCP prophylaxis with aerosolized pentamidine. METHODS: A total of 121 HIV-infected patients with CD4+ cell counts