Archives of environmental health最新文献

In this pilot study, conducted in summer 2002, the authors measured blood lead levels (BLLs) for 118 subjects in the city of Trujillo, Peru, where leaded gasoline is in the process of being phased out. Subjects included bus drivers, combi (minivan) drivers, street vendors, newspaper vendors, traffic police, taxi drivers, gas station attendants, children living both near and distant from gas stations, pregnant women, and office workers (controls). The highest BLLs were 9.2 microg/dl and 9.3 microg/dl from a child who lived near a gas station and from a traffic policeman, respectively; however, all BLLs were below the U.S. Centers for Disease Control and Prevention's advisory level of concern (10 microg/dl). Office workers (n = 8) and pregnant women (n = 36) had significantly lower BLLs (geometric mean +/- standard deviation = 2.1 +/- 0.7 microg/dl, p < 0.022; and 2.5 +/- 1.1 microg/dl, p < 0.008, respectively) than total traffic-exposed workers (n = 48; 3.2 +/- 1.8 microg/dl). BLLs of children living near gas stations (n = 17; 3.7 +/- 2.2 microg/dl) were marginally higher (p = 0.07) than for children not living near gas stations (n = 9; 2.9 +/- 1.1 microg/dl). The study was limited by small sample size and the fact that the data were based on a convenience sample not fully representative of the cohorts studied. Nevertheless, the authors' findings suggest that leaded gasoline use in Trujillo continues to affect BLLs in traffic-exposed populations.

In this study, the authors assessed the relationship between daily changes in respiratory health and particulate levels with diameters of (a) less than 10 microm (PM10) and (b) less than 2.5 microm (PM2.5) in Kanpur, India. The subjects (N = 91) were recruited from 3 areas in Kanpur: (1) Indian Institute of Technology (Kanpur), which was a relatively clean area; (b) Vikas Nagar, a typical commercial area; and (c) finally, the residential area of Juhilal Colony. All subjects resided near to air quality monitoring sites. Air quality and peak expiratory flow rate samplings were conducted for 39 d. Once during the sampling period, lung-function tests (i.e., forced expiratory volume in 1 s, forced vital capacity) were performed on each subject. Subjects who resided at the clean site performed at predicted (i.e., acceptable) values more often than did subjects who lived at the remaining 2 sites. Subjects who lived at all 3 sites demonstrated a substantial average deficit in baseline forced vital capacity and forced expiratory volume in 1 s values. The authors used a statistical model to estimate that an increase of 100 microg/m3 of the pollutant PM10 could reduce the mean peak expiratory flow rate of an individual by approximately 3.2 l/min.

Flight attendants (FAs) exposed to insecticide spray in an aircraft were compared with unexposed subjects for neurobehavioral function, pulmonary function, mood states, and symptoms. The 33 symptomatic FAs were self-selected, and 5 had retired for disability. Testing procedures included balance, reaction time, color discrimination, visual fields, grip strength, verbal recall, problem solving, attention and discrimination functions, and long-term memory functions. Measurements were expressed as a percentage of their predicted values (derived from unexposed controls), and the author compared the means of the percentage predicted values by analysis of variance. Symptom frequencies and Profile of Mood States (POMS) scores were assessed. FAs were significantly more impaired than controls with respect to balance with eyes closed, grip strength, and color discrimination. Nearly half had 3 or more abnormal neurobehavioral functions, after adjustment was made for age, sex, and education level. Neither elevated POMS scores nor frequencies of average symptoms correlated with their numbers of abnormal measurements. Occupational exposure to synthetic pyrethrin insecticides on airliners was associated with neurobehavioral impairment and disability retirement.

The authors conducted a telephone survey of 1054 randomly selected individuals within the continental United States to determine the prevalence of chemical hypersensitivity and the medical diagnosis of multiple chemical sensitivity (MCS) in the American population. The etiology and symptomatology of MCS also were investigated. Results produced a 95% confidence level and a +/-3% margin of error. The authors found that 11.2% of Americans reported an unusual hypersensitivity to common chemical products such as perfume, fresh paint, pesticides, and other petrochemical-based substances, and 2.5% reported they had been medically diagnosed with MCS. Additionally, 31.1% of those sampled reported adverse reactions to fragranced products, and 17.6% experienced breathing difficulties and other health problems when exposed to air fresheners. Although chemical hypersensitivity was more common in women, it affected individuals in all demographic groups studied.

To date, no study has effectively demonstrated a direct human exposure to mycotoxins in mold-contaminated buildings. Therefore, the authors investigated the presence of trichothecene mycotoxins in sera from individuals exposed to indoor molds (specifically Stachybotrys chartarum). Sera from occupants of contaminated (test samples, n=44) and uncontaminated (control samples, n=26) buildings were analyzed using a competitive enzyme-linked immunosorbent assay (ELISA) highly specific for macrocyclic trichothecenes. Twenty-three samples were significantly different (p < 0.05) from normal human serum tested in the same manner, whereas only 1 of the control samples tested positive. Mass spectrometry analysis could not confirm the presence of intact S. chartarum macrocyclic trichothecenes. The authors hypothesize that this result was caused by uncharacterized ELISA-reactive metabolic breakdown products. Data from this study suggest that trichothecene mycotoxins can be demonstrated in the tissues of certain individuals exposed to S. chartarum in contaminated buildings.

More than 32 million people in the United States suffer from chronic lung diseases; 12 million experienced at least one asthma attack in 2002. The causes of this "epidemic" are complex and uncertain; however, there is a strong possibility that environmental exposures play a role. The most common and well-studied cause of occupational asthma is diisocyanates, but their use in consumer products as a potential cause of respiratory disease in the general population has been overlooked. These substances are found in or are used to produce an array of polyurethane-containing products, including adhesives, sealants, paints, flexible foams, and rigid foams, among others. The world market for polyurethane products has tripled since 1985 to more than 9.3 billion kg in the year 2000. In this article, the author reviews biologically plausible explanations, as well as the epidemiologic, experimental, and clinical evidence for the role of diisocyanates and polyurethanes in the genesis of nonoccupational allergy and respiratory disease.

This study was conducted to assess the quality of interview-based exposure estimates obtained in a large epidemiologic case-control study: The Northern Germany Leukemia and Lymphoma Study (1997-2002) (NLL). The NLL used standardized, face-to-face, computer-assisted interviews to record subjects' lifetime use of radiofrequency (RF)-emitting appliances such as cellular telephones, cordless telephones, baby monitors, and television headphones. Exposure assessment comprised 3 levels of precision: ever use, gross vs. net appliance-years, and lifetime cumulative exposure hours. In the current study, the authors analyzed data from 3041 interviews of NLL controls, representing an age-stratified random sample of the general populations of 6 counties in Northern Germany. Weighted kappa coefficients for gross vs. net appliance-years for men were 0.59 (95% confidence interval [CI] = 0.46, 0.71) for baby monitors and 0.98 (95% CI = 0.97, 0.99) for cordless phones; for women, the coefficients were 0.68 (95% CI = 0.56, 0.79) and 0.97 (95% CI = 0.94, 0.98), respectively. Weighted kappa values were considerably lower when net appliance-years and lifetime cumulative exposure hours were compared. Study results demonstrated that interview information on use of RF-emitting appliances, when measured at different levels of precision, can result in misclassification and biased risk estimates.

In this study, the authors examined the health risks to 1234 residents (15-80 yr of age) who lived near a lead-zinc mine and to 801 controls (15-80 yr of age) who lived 40 km from the mine. Subjects had higher levels of urinary cadmium, urinary beta2-microglobulin, and N-acetyl-beta-glucosaminidase (NAG) than controls (p < 0.0001), but subjects' urinary beta2-microglobulin and NAG were within normal ranges. Standardized death rates for cancer in the contaminated and control areas were 116.7/100,000 and 90.28/100,000, respectively, and for neonatal disease the respective rates were 89.83/100,000 and 16.74/100,000. Young girls residing in the contaminated areas had higher menstrual abnormalities than did controls (p = 0.002). The prevalence of difficulties in becoming pregnant and the proportion of premature births and stillbirths were higher among those in the contaminated areas (p < 0.0001). Individuals who lived around the lead-zinc mine had different health problems than those who lived far from the mine in Zhenhe County, Republic of China.

The authors have developed a dynamic headspace (purge-and-trap) gas chromatographic method, with photoionization detection, for the determination of benzene (C6H6), toluene (C7H8), ethylbenzene (C8H10), and isomeric (o-, m-, p-) xylenes (C8H10) (BTEX) in urine. Detection limits ranged between 15 and 35 ng/l, relative standard deviations between 0.2 and 10%, and accuracy between 80 and 100%. The primary objective of this study was to use this new method to establish baseline concentration data for BTEX in the urine of the general population of Zagreb, Croatia. A second objective was to evaluate the effect of cigarette smoking on those baseline values. BTEX were analyzed in the urine of 72 subjects (36 nonsmokers and 36 smokers) without occupational exposure to BTEX. The nonsmokers had measurable BTEX in their urine, except for ethylbenzene in 13 and o-xylene in 15 of the samples. Values for BTEX were markedly higher among smokers than nonsmokers. Because the sources of BTEX exposure are commonly derived (i.e., vehicle exhausts and smoking), their values in subjects' urine were significantly intercorrelated. Levels of toluene and o-xylene were correlated significantly with the number of cigarettes smoked per day. The use of purge-and-trap gas chromatography with photoionization detection to determine BTEX in urine offers a convenient approach for biological monitoring of the general population. Study data provide referent values for BTEX in urine, which can be used as biomarkers for environmental exposures. Smoking contributes significantly to the urinary concentration of BTEX.

In this study, the author examined the cross-reactivities of Stachybotrys chartarum, Aspergillus niger/fumigatus, and Penicillium notatum with affinity-purified rabbit sera. The molds were grown for expression of maximum numbers of antigens, after which they were extracted and mixed with commercially available extracts. The mixture was used for antibody preparation in rabbits, measurement of antibody levels, and for the demonstration of the degree of cross-reactivity. Control rabbits were injected with saline, yet they produced significant levels of immunoglobulin G antibodies against all mold extracts tested. The author interpreted this result to mean that sera obtained from rabbits immunized with pure mold extracts likely reflected cross-reactivity with other molds. Therefore, only affinity-purified antibodies and the most sensitive immunoassay technique (i.e., enzyme-linked immunosorbent assay [ELISA]) were used for the cross-inhibition studies. The antigenic cross-reactivities were as follows: (a) between Aspergillus and Penicillium, 19.6-21.0%; (b) between Stachybotrys and Aspergillus, 8.2-8.7%; and (c) between Stachybotrys and Penicillium, 7.0-9.6%. The findings of this study demonstrate that cross-reactivity studies between different molds require the use of affinity-purified antibodies and a sensitive and quantitative assay with untreated antigens. With the use of such an assay, it was determined that the cross-reactivity between Stachybotrys, Aspergillus, and Penicillium was at approximately 10%, which is less widespread than previously believed.