Spirometric function in non-smoking workers exposed to aluminum

Dietary unsaponifiable fraction of extra virgin olive oil supplementation attenuates lung injury and DNA damage of rats co-exposed to aluminum and acrylamide

Aluminum chloride (AlCl3) and acrylamide (ACR) are well known as environmental pollutants inducing oxidative stress. Our study investigated the effects of these contaminants and if the hydrophilic fraction of extra virgin olive oil was able to prevent lung oxidative stress and DNA damage. Animals were divided into four groups of six each: group 1, serving as controls, received distilled water; group 2 received in drinking water aluminum chloride (50 mg/ kg body weight) and by gavage acrylamide (20 mg/kg body weight); group 3 received both aluminum and acrylamide in the same way and the same dose as group 2 and hydrophilic fraction from olive oil (OOHF) (1 ml) by gavage; group 4 received only OOHF by gavage. Exposure of rats to both aluminum and acrylamide provoked oxidative stress in lung tissue based on biochemical parameters and histopathological alterations. In fact, we have observed an increase in malondialdehyde (MDA), H2O2, and advanced oxidation protein product (AOPP) and a decrease in reduced glutathione (GSH), non-protein thiols (NPSH), and vitamin C levels. Activities of catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD) were also decreased. Histopathological changes in lung tissue were noted like emphysema, vascular congestion, and infiltration of inflammatory cells. A random DNA degradation was observed on agarose gel in the lung of AlCl3 and acrylamide (ACR)-treated rats. Co-administration of OOHF to treated rats improved biochemical parameters to near control values and lung histoarchitecture. The smear formation of genomic DNA was reduced. The hydrophilic fraction of extra virgin olive oil might provide a basis for developing a new dietary supplementation strategy in order to prevent lung tissue damage.

Altered methylation in tandem repeat element and elemental component levels in inhalable air particles

Exposure to particulate matter (PM) has been associated with lung cancer risk in epidemiology investigations. Elemental components of PM have been suggested to have critical roles in PM toxicity, but the molecular mechanisms underlying their association with cancer risks remain poorly understood. DNA methylation has emerged as a promising biomarker for environmental-related diseases, including lung cancer. In this study, we evaluated the effects of PM elemental components on methylation of three tandem repeats in a highly exposed population in Beijing, China. The Beijing Truck Driver Air Pollution Study was conducted shortly before the 2008 Beijing Olympic Games (June 15-July 27, 2008) and included 60 truck drivers and 60 office workers. On two days separated by 1-2 weeks, we measured blood DNA methylation of SATα, NBL2, D4Z4, and personal exposure to eight elemental components in PM2.5 , including aluminum (Al), silicon (Si), sulfur (S), potassium (K), calcium (Ca) titanium (Ti), iron (Fe), and zinc (Zn). We estimated the associations of individual elemental component with each tandem-repeat methylation in generalized estimating equations (GEE) models adjusted for PM2.5 mass and other covariates. Out of the eight examined elements, NBL2 methylation was positively associated with concentrations of Si [0.121, 95% confidence interval (CI): 0.030; 0.212, False Discovery Rate (FDR) = 0.047] and Ca (0.065, 95%CI: 0.014; 0.115, FDR = 0.047) in truck drivers. In office workers, SATα methylation was positively associated with concentrations of S (0.115, 95% CI: 0.034; 0.196, FDR = 0.042). PM-associated differences in blood tandem-repeat methylation may help detect biological effects of the exposure and identify individuals who may eventually experience higher lung cancer risk.

Regular exercise training attenuates pulmonary inflammatory responses to inhaled alumina refinery dust in mice

Exposure to alumina dust has been recently associated with impaired lung mechanics and inflammation. We aimed at evaluating if moderate exercise training prevents these outcomes. Twenty-three female BALB/c mice (25-30g) were randomly divided in two main groups: control (C) and exercise (E), which were submitted, or not, to 15min of swimming, 5 days/week during 4 weeks. Then, the animals were exposed for 1h to either saline solution (CS or ES) or to a suspension of 8mg/m(3) of alumina dust (CA or EA). Twenty-four hours later pulmonary mechanics was determined by the end-inflation occlusion method. Left lungs were prepared for histology and right lungs for TGF-β determination. Static elastance increased after alumina dust exposure independently of swimming. In CA group the viscoelastic component of elastance, the viscoelastic/inhomogeneous pressure, the polymorphonuclear amount, the fraction area of alveolar collapse and TGF-β increased. Thus, exercise training may mitigate the pro-inflammatory response to inhaled aluminum refinery dust.

Impact of aluminum exposure on lung

Aluminum (Al) metal is considered one of the most benign industrial metals. Although the harmful effects of Al on respiratory health have been denied by some studies, others reported its noxious effect on the lung through spirometric measurements. This work aimed at studying the effect of Al fumes on pulmonary functions of occupationally exposed workers. It investigated the possible relationship between inhalation exposure to Al fumes and levels of C-reactive protein (CRP) and alpha-1-antitrypsin (A1AT). The study participants comprised a group of 56 male Al workers with a mean duration of occupational exposure of 10.1 ± 9.5 years and 52 male participants who were not exposed to Al fumes as the control group. All participants filled a questionnaire, underwent full clinical examination and their spirometric pulmonary functions were measured. Blood samples were collected for the determination of serum CRP and A1AT and urine samples for measuring Al. Results revealed that urinary Al (UAl) was significantly higher in Al workers compared with controls (p < 0.05). However, spirometric measures showed no significant difference between the exposed group and the controls. A1AT was significantly lowered in Al workers compared with the controls (p < 0.000). Serum CRP was positive in only two (3.6%) of the exposed workers. Smokers of both groups (exposed and controls) showed significantly higher UAl and lower A1AT compared with nonsmokers. There was only significant negative correlation between the duration of exposure and A1AT (p < 0.05). There was a positive significant correlation between smoking index (SI) and UAl. There was also significant negative correlation between SI and some of the pulmonary function tests namely the percentage of predicted forced vital capacity, forced expiratory volume in the first second and peak expiratory flow in the exposed group. Those correlations point to the importance of the combined effect of smoking and Al exposure on the impairment of lung functions. The study recommends the determination of CRP and A1AT in Al-exposed workers. It is expected that those parameters may undergo changes before reduction in pulmonary functions takes place.

Early neurotoxic effects of inhalation exposure to aluminum and/or manganese assessed by serum levels of phospholipid-binding Clara cells protein

Little is known on the disturbances of lung epithelium function in aluminum casting smelters and shipyard welders exposed by inhalation to irritant occupational pollutants, dust and fumes. The exact mechanism of aluminum and manganese toxicity is not known, but it is thought that they may potentiate oxidative and inflammatory stress, leading to impaired neurological function. The aim of the study was to investigate the subclinical effects of aluminum and manganese exposure on the nervous system and to assess their relationship to the biomarkers of exposure and effect in workers exposed to neurotoxic fumes. The relationship between the neurological and respiratory effects was investigated in 50 workers at aluminum casting smelters exposed to x(GM) = 0.29 Al(2)O(3) mg m(-3), and 59 shipyard welders exposed to x(GM) = 0.16 Mn mg m(-3), and the reference group. Serum anti-inflammatory, phospholipid-binding Clara cell protein (CC16) as a peripheral marker of the bronchiolar epithelium function measured. The lowest CC16 concentrations were found in workers showing subjective CNS symptoms and abnormal neurophysiological findings: EEG and visual evoked potentials. A strong inverse relationship was found between serum Al (Al-S) and CC16 concentrations (p = 0.006). Younger smelter workers and welders, with a shorter exposure duration, presented a higher number of VEPs than the workers employed for a longer period of time. The sub-clinical neurological symptoms (VEP) and low CC16 level can be associated with an internalization of Al ions with lipid fractions of the lung epithelium, which in turn may help Al ions overcome the blood-brain barrier. The inhibited secretion of anti-inflammatory Clara cell protein and low respiratory performance in younger Mn welders was found to enhance subclinical neurotoxic symptoms, especially VEPs, related to exposure to airborne Mn and Mn-B.

Characterization of contamination in and toxicities of a shipyard area in Hong Kong

This is the first integrated study on the contaminant characterization and toxicities of a shipyard area. This site in Hong Kong contained 3.6-33.4 mg kg(-1) dichlorodiphenyltrichloroethane and 5-79 g kg(-1) oil and grease. Other pollutants exceeding the Dutch intervention values were total polyaromatic hydrocarbons, total petroleum hydrocarbons, and metals Cu, Pb and Zn. These pollutants persisted partially owing to the poor fertility with <125 mg N kg(-1) and <530 mg P kg(-1) typical of coastal soil. Sediments collected within 100 m also showed contamination exceeding the China and Hong Kong intervention levels. The shipyard soil killed two bacteria Pseudomonas stutzeri and Acinetobacter sp. isolated from a clean coastal soil, inhibited germination of three exogenous plants Triticum aestivum, Brassica chinense and Lolium perenne, and inhibited proliferation of three indigenous bacteria: Methylobacterium sp., Pseudomonas aeruginosa and Bacillus cereus. Thus, ex situ remediation was needed.

Serum Clara Cell Protein as an Indicator of Pulmonary Impairment in Occupational Exposure at Aluminum Foundry

OBJECTIVES

Although some of the exposures in aluminum (Al) smelting have been well characterized, and respiratory disorders in aluminum production workers are well known, the relationship between internal aluminum loads and appropriate lung biomarkers have not been elucidated. The aim of our work was to carry out a comprehensive investigation in workers employed in the Aluminum Foundry Casting Department with special reference to currently existing hygiene standards, known as threshold limit values (TLV) based on aluminum effects on the respiratory system. The measurement of serum anti-inflammatory Clara cell protein (CC16) was employed as a peripheral marker of the lung epithelium function.

MATERIALS AND METHODS

A group of 50 casting smelters, 5 locksmiths, 11 sawyers and auxiliary workers exposed to dust containing 14% of aluminum, and a group of 42 controls were examined. Respiratory function tests were performed and forced volume capacity (FVC), forced expiratory volume in 1 s (FEV1), forced expiratory volume in the first percent (FEV1%), forced expiratory flows in 50% VC (FEV50), and markers of foundry workers' exposure and body burden, Al concentration in the breathing zone, blood and urine, biomarkers of the effects of exposure, concentration of CC16 and hyaluronic acid (HA) in serum were determined in all examined workers. Additional measurements comprised determinations of serum iron (Fe) levels, myeloperoxidase (MPO), eosinophil cationic protein (ECP), immunoglobulin E (IgE), glutathione S-transferase (GST), and superoxide dismutase (SOD) activity in erythrocytes.

RESULTS

The group of casting smelters was characterized by the highest levels of aluminum in urine (Al-U) (43.7 microg L(-1)), high levels of MPO, ECP and IgE, high SOD activity, low CC16 levels, and low activity of GST. Lower Al-U excretion was observed in locksmiths (35.2 microg L(-1)) and sawyers (21.7 microg L(-1)). Serum CC16 proved to be the most sensitive biomarker, showing high inverse relationship with serum Al (Al-S) concentrations in casting smelters (p = 0.006).

CONCLUSIONS

The study showed that in conditions of occupational exposure, dusts containing Al2O3 < 1 mg m(-3) cause changes in the respiratory system and biomarkers in serum, especially in CC16, connected with altered functioning of this system. Changes in concentrations of the examined biomarkers and also in respiratory parameters of the study subjects were observed when Al-U concentration was > 40 microg L (-1).