Tadeusz Halatek

Relation between sources of particulate air pollution and biological effect parameters in samples from four European cities: An exploratory study

Given that there are widely different prevalence rates of respiratory allergies and asthma between the countries of Europe and that exposure to ambient particulate matter (PM) is substantial in urban environments throughout Europe, an EU project entitled “Respiratory Allergy and Inflammation Due to Ambient Particles” (RAIAP) was set up. The project focused on the role of physical and chemical composition of PM on release of cytokines of cells in vitro, on respiratory inflammation in vivo, and on adjuvant potency in allergy animal models. Coarse (2.5–10 μm) and fine (0.15–2.5 μm) particles were collected during the spring, summer and winter in Rome (I), Oslo (N), Lodz (PL), and Amsterdam (NL). Markers within the same model were often well correlated. Markers of inflammation in the in vitro and in vivo models also showed a high degree of correlation. In contrast, correlation between parameters in the different allergy models and between allergy and inflammation markers was generally poor. This suggests that various bioassays are needed to assess the potential hazard of PM. The present study also showed that by clustering chemical constituents of PM based on the overall response pattern in the bioassays, five distinct groups could be identified. The clusters of traffic, industrial combustion and/or incinerators (TICI), and combustion of black and brown coal/wood smoke (BBCW) were associated primarily with adjuvant activity for respiratory allergy, whereas clusters of crustal of material (CM) and sea spray (SS) are predominantly associated with measures for inflammation and acute toxicity. The cluster of secondary inorganic aerosol and long-range transport aerosol (SIALT) was exclusive associated with systemic allergy. The present study has shown that biological effect of PM can be linked to one or more PM emission sources and that this linkage requires a wide range of bioassays.

Association between occupational exposure to arsenic and neurological, respiratory and renal effects

Occupational exposure by inhalation in copper smelter is associated with several subclinical health phenomena. The respiratory tract is usually involved in the process of detoxication of inhaled noxious agents which, as arsenic, can act as inductors of oxidative stress (Lantz, R.C., Hays, A.M., 2006. Role of oxidative stress in arsenic-induced toxicity. Drug Metab. Rev. 38, 791-804). It is also known that irritating fumes affect distal bronchioles of non-ciliated, epithelial Clara cells, which secrete anti-inflammatory and immunosuppressive Clara cell protein (CC16) into the respiratory tract. The study group comprised 39 smelters employed at different workplaces in a copper foundry, matched for age and smoking habits with the control group (n=16). Subjective neurological symptoms (SNS), visual evoked potentials (VEP), electroneurographic (EneG) and electroencephalographic (EEG) results were examined in the workers and the relationships between As concentration in the air (As-Air) and urine (As-U) were assessed. Effects of exposure were expressed in terms of biomarkers: CC16 as early pulmonary biomarker and beta(2)-microglobulin (beta(2)M) in urine and serum and retinol binding protein (RBP) as renal markers, measured by sensitive latex immunoassay. The concentrations of arsenic exceeded about two times the Threshold Limit Values (TLV) (0.01 mg/m(3)). The contents of lead did not exceed the TLV (0.05 mg/m(3)). Low CC16 levels in serum (12.1 microg/l) of workers with SNS and VEP symptoms and highest level As-U (x(a) 39.0 microg/l) were noted earliest in relation to occupational time. Moreover, those effects were associated with increased levels of urinary and serum beta(2)M and urinary RBP. Results of our study suggested the initiative key role of oxidative stress in triggering the processes that eventually lead to the subclinical effects of arsenic on the nervous system.

EffEcts of occupational ExposurE to arsEnic on tHE nErvous systEm: clinical and nEuropHysiological studiEs

OBJECTIVES A number of metals, especially heavy metals, exhibit neurotoxic properties. Neurological and neurophysiological studies indicate that the functions of the central (CNS) and peripheral nervous system (PNS) may be impaired under conditions of exposure to arsenic (As). The aim of the present study was to assess the effects of inorganic arsenic on the central and peripheral nervous system. MATERIALS AND METHODS The study covered a group of 21 male workers (mean age: 41.9 yr; SD: 7.6; range: 31-55 yr) employed in a copper smelting factory. Their employment duration ranged from 5 to 33 years (mean: 18.1 yr; SD: 7.8). Arsenic concentrations in workplace air amounted to 0.01003 mg/m3 on average (SD: 0.00866). Urine arsenic concentrations ranged from 3.48 to 23.63 μg/l (mean: 11.91 μg/l; SD: 9.5). The control group consisted of 16 males non-occupationally exposed to As, matched for gender, age and work shift pattern. The evaluation of neurological effects was based on the findings of neurological examination, electroencephalography (EEG), visual evoked potentials (VEPs) and electroneurography (ENeG). RESULTS Clinical symptoms, such as sleeplessness or sleepiness, irritability, headache, painful spasms in extremity muscles, extremity paresthesia and pain, and muscular fatigue prevailed among functional disorders of the nervous system in workers chronically exposed to As. Neurological examination did not reveal any organic lesions in the CNS or PNS. In EEG records classified as abnormal, generalized changes were most common. VEP examinations revealed abnormalities in evoked response latency. Stimulation of the motor fibers of the peroneal and medial nerves resulted in a decreased amplitude of the motor potential. Stimulation of the sensory fibers of medial nerves brought about a decreased amplitude of the sensory potential and a lower conduction velocity of the sural nerves. CONCLUSION The findings of the study indicate that exposure to As concentrations within the threshold limit values (TLV) can induce subclinical effects on the nervous system, especially subclinical neuropathy.

The inflammatory response in lungs of rats exposed on the airborne particles collected during different seasons in four European cities

Epidemiological studies have reported associations of ambient particulate air pollution, especially particulate matter (PM) less than 10 μm with exacerbations of asthma and chronic obstructive pulmonary disease. In an in vivo model, we have tested the toxicity of urban airborne particles collected during spring, summer, and winter seasons in four cities (Amsterdam, Lodz, Oslo, and Rome) spread across Europe. The seasonal differences in inflammatory responses were striking, and almost all the study parameters were affected by PM. Coarse fractions of the urban particle samples were less potent per unit mass than the fine fractions in increasing cytokine [macrophage inflammatory protein (MIP)-2 and tumor necrosis factor (TNF)-α] levels and in reducing Clara-cell secretory protein (CC16) levels. This study shows that PM collected at 4 contrasting sites across Europe and during different seasons have differences in toxic potency. These differences were even more prominent between the fine and coarse fractions of the PM.

Serum Clara-Cell Protein and β2-Microglobulin as Early Markers of Occupational Exposure to Nitric Oxides

Abstract Biochemical effects of NOx on 60 workers (both genders) of nitric acid production were studied. The control group consisted of 61 nonexposed people employed elsewhere in the plant. Although the actual threshold limit value–time weighted averages (TLV-TWA) were not exceeded in the specific conditions of our study, the subjects were exposed to NObm2 and NO during several exposure episodes with peak maximal concentrations of 140 ppm and 515 ppm, respectively. Additional cross-week evaluation of several biochemical biomarkers in 15 NOx-exposed workers from one shift was performed. The objective of the study was to evaluate the value of serum Clara-cell protein (CC16) as a marker of bronchoalveolar epithelium activity. Antioxidant status was assessed by measuring activity of enzymes: glutathione peroxidase (GSH-Px), ceruloplasmin (Cp) in plasma, or superoxide dismutase (SOD), gluthatione S-transferase (GST), and nonenzymatic α-tocopherol in erythrocytes and thiobarbituric acid-reactive substances (TBARS) in plasma. Serum hyaluronic acid (HA) determining the connective tissue matrix status of airways, and β2-microglobulin in serum (β2M-S) and urine (β2M-U) as a marker of renal function in occupational exposure to NOx were also employed. Exposure to NOx initiates peroxidative chain depleting of lipoprotein pool (α-tocopherol) in blood. Serum CC16 levels in NOx-exposed workers were found to be closely connected with α-tocopherol content. In NOx-exposed workers, the β2M-S level was significantly higher than in the nonexposed ones, with the exception of smokers. Results of the cross-week study confirm cumulative systemic effects of NOx on several examined biomarkers. SOD and GST were found to be depleted. A transient higher level of HA after a 5-d shift significantly inversely correlated with CC16 level. The data imply that NOx-depleted levels of CC16 are detectable already after an 8-h shift. Our results demonstrate that even low NOx human exposure can cause characteristic changes in bronchiolar epithelium cells and renal effects. Serum CC16 level, although a nonspecific marker, was lowest in NOx-exposed subjects. The most sensitive parameters in exposed workers were β2M-S and α-tocopherol. Spirometric assessment was not useful to describe low occupational exposure to NOx. In studying the effects of NOx on biomarkers, it is essential to carefully select suitable time of sampling. Screening of CC16, β2M-S, and α-tocopherol can be successfully employed for biological monitoring of exposure to NOx.

Pulmonary Irritation After Inhalation Exposure to Benzalkonium Chloride in Rats

BACKGROUND Benzalkonium chloride (BAC) is a quaternary ammonium compound (QAC) with a C8 to C18 chain length of alkyl groups. Since BAC exerts toxic effects on microorganisms, it has been used as an effective germicide and preservative, mostly in cosmetic industry and medicine. However, the toxic potential of BAC may be hazardous to humans, due to the common use of preparations containing BAC as a preservative. MATERIAL AND METHODS To assess the possible toxic effects of BAC, two-stage experiments were performed on female Wistar rats. At first, LC50 after a single exposure to BAC aerosol was determined. Then, the animals were exposed to BAC aerosol at 30 mg/m3 for 6 h, and for 3 days (6 h/day). The controls were unexposed rats. Directly after BAC exposure and 18 h afterwards, BALF concentrations were measured of total protein, Clara cell protein, matrix metalloproteinase-9 (MMP-9), hyaluronic acid (HA), immunoglobulin E (IgE) and cytokines (TF-alpha, IL-6 and MIP-20), lactate dehydrogenase (LDH) and GSH-S-transferase (GST). RESULTS The LC50 value for exposed rats was ca. 53 mg BAC in m3 air for 4 h. All the rats survived single and repeated inhalation exposure to 30 mg/m3 BAC. After single and repeated exposure, lung weight, total protein, HA and LDH activity in BALF of exposed rats were higher than in controls while CC16 levels were decreased. A significantly higher BALF concentration of IL-6 and IgE was noted in animals exposed to single and repeated doses. BALF concentrations of MMP-9, TNF-alpha, and MIP-2 in exposed rats were similar to those in control animals. CONCLUSION BAC may be classified to class I acute inhalation toxicity. It showed a strong inflammatory and irritant activity on the lungs after 6h inhalation and stimulated dynamic patterns of IL-6 and IgE production and protein infiltration from blood vessels to BALF. Continued exposure resulted in cellular destruction, a statistically significant increase in LDH activity and a continuous decrease in CC16 concentration in BALF.

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 xGM = 0.29 Al2O3 mg m− 3, and 59 shipyard welders exposed to xGM = 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.

Increased oxidative stress in subjects exposed to carbon disulfide (CS2) – an occupational coronary risk factor

Abstract. There is considerable epidemiological evidence that workers exposed to carbon disulfide (CS2) develop premature atherosclerosis leading to increased rates of coronary heart disease (CHD), but mechanisms underlying this association remain obscure. The present study documents that occupational exposure to CS2 modifies the oxidative status of plasma, which is a major determinant of the susceptibility to atherosclerosis. Concentrations of thiobarbituric reactive substances (TBARS), which reflect lipid peroxidation processes in plasma, were determined in 29 men who were exposed to CS2 for more than 20 years, in 24 patients with peripheral atherosclerosis, and in 30 unexposed, healthy control subjects. TBARS concentrations were significantly increased both in CS2-exposed subjects and in patients with peripheral atherosclerosis. Subjects in both groups presented also with decreased levels of plasma α-tocopherol, a major plasma antioxidant. In addition, decreased activities of two enzymatic antioxidants, glutathion peroxidase and catalase, were noted both in CS2-exposed subjects and patients with peripheral atherosclerosis. Finally, LDL isolated from both groups showed increased susceptibility to transition metal-induced oxidation in vitro. It is concluded, that occupational exposure to CS2 produces oxidative stress in plasma. This may favor the development of atherosclerosis and increase the incidence of CHD in workers exposed to CS2.

Health effects and arsenic species in urine of copper smelter workers

The aim of this study was to compare indices of exposure in workers employed at different work posts in a copper smelter plant using neurophysiological tests and to evaluate the relationship between urinary arsenic species with the aid of sensitive respiratory and renal biomarkers. We have attempted to elucidate the impact of different arsenic speciation forms on the observed health effects. We focused on the workers (n = 45) exposed to atmospheres containing specific diverse mixtures of metals (such as those occurring in Departments of Furnaces, Lead and Electrolysis) compared to controls (n = 16). Subjective symptoms from the central (CNS) and the peripheral (PNS) nervous system were recorded and visual evoked potential (VEP), electroneurography (ENeG) and electroencephalography (EEG) curves were analysed. Levels of airborne lead (PbA), zinc (ZnA) and copper (CuA) and Pb levels in blood (PbB) and the relationships between airborne As concentrations (AsA) and the urinary levels of the inorganic (iAs); As(+3), As(+5) and the organic; methylarsonate (MMA(V)), dimethylarsinate (DMA(V)) and arsenobetaine (AsB) arsenic species were determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Effects of exposure were expressed in terms of biomarker levels: Clara cell protein (CC16) in serum as early pulmonary biomarker and β2-microglobulin (β2M) in urine and serum, retinol binding protein (RBP) as renal markers, measured by sensitive latex-immunoassay (LIA). Abnormal results of neurophysiological tests, VEP, EEG and ENeG showed dominant subclinical effects in CNS and PNS of workers from Departments of Lead and Furnace. In group of smelters from Departments of Furnace exposed to arsenic above current TLV, excreted arsenic species As(+3) and As(+5) seemed to reduce the level of Clara cell protein (CC16), thereby reducing anti-inflammatory potential of the lungs and increasing the levels of renal biomarker (β2M) and copper in urine (CuU). The study confirmed deleterious arsenic effects to the kidney by increased levels of low-molecular weight protein in urine and the extent of the renal copper accumulation/excretion. The results of our work also support the usefulness of application of the sensitive neurophysiologic tests, such as VEP, EEG and ENeG, for the detection of early subclinical effects of the exposure of the nervous system in copper smelters.

Glutaraldehyde Inhalation Exposure of Rats: Effects on Lung Morphology, Clara-Cell Protein, and Hyaluronic Acid Levels in BAL

Glutaraldehyde (GA) is a biocide widely used in hospital and laboratory practice. GA is a volatile substance and, under certain circumstances, significant airborne concentrations may be generated at room temperature. Occupational exposure to GA by inhalation is suspected of causing delayed irritating effects. In recent years, GA has emerged as the main cause of occupational asthma among health-care workers. The aim of the present study was to evaluate effects of GA inhalatory exposure (0.025 ppm or 0.1 ppm, for 28 days) in rats exposed corresponding to the occupational shift cycle, at time point 24 h, 48 h, and 7 days postexposure (PE). Numerous vacuoles and dilated spaces in epithelial cells in bronchioles showing a destructive effect of GA on the cellular membrane were observed at 24 h PE in 0.1 ppm exposed rats. Lipid vacuoles observed after 48 h PE in higher GA exposure, in the Clara cells of the bronchial epithelium, and in endothelial cells of the alveolar capillaries are probably attributable to disturbed lipid metabolism. Many foci of collagen fibers were observed already after 7 days postexposure. Monitoring of inflammatory response and repair was made possible by using two biomarkers: Clara-cell protein (CC16) and hyaluronic acid (HA). Our results show that the inflammatory repair response contributed to progenitor Clara cells and HA plays a role in the development of fibrotic changes in the lung of rats. Glutaraldehyde in rats causes fibrotic effects at the actual threshold limit value-time weighted average (TLV-TWA) level for GA as specified by current Polish and other national regulations.