Occupational exposure to nickel salts in electrolytic plating

An occupational hygiene survey was made in 38 nickel plating shops in Finland and exposure to nickel was studied by means of biological measurements and, in three shops, by using air measurements. The average after-shift urinary nickel concentration of 163 workers was 0.16 μmol l.⁻¹ (range 0.001–4.99 μmol l.⁻¹). After the 1–5 week vacation the urinary nickel concentration was higher than the upper reference limit of non-exposed Finns indicating that a part of water-soluble nickel salts is accumulated in the body. Urinary nickel concentrations in the shops considered clean in the industrial hygiene walk-through were not different from those observed in the shops considered dirty. The correlation between the concentrations of nickel in the air and in the urine was low, and the amount of nickel excreted in the urine exceeded the calculated inhaled amounts, indicating exposure by other routes such as ingestion.     

Urinary elimination of nickel and cobalt in relation to airborne nickel and cobalt exposures in a battery plant

Objective To estimate the relationship between Ni concentrations in the ambient air and in the urine, at a battery plant using nickel hydroxide. Methods Workers occupationally exposed to a mixture of nickel hydroxide, metallic cobalt and cobalt oxyhydroxide dust were studied during two consecutive workdays. Air levels of Ni and Co in total dust were determined by personal sampling in the breathing zone. Both metals in air were sampled by Teflon binder filters and analyzed by inductively coupled plasma absorption emission spectrophotometry. Urine was collected from 16 workers immediately before and after the work shift. Urinary Ni and Co concentrations were measured by electrothermal atomic absorption spectrometry. Results A poor correlation was seen between Co in the air and in post-shift urine (r = 0.491; P < 0.01), and no correlation was found between Ni in the air and in post-shift urine (r = 0.272; P = 0.15), probably due to the use of respiratory protection. The subjects were exposed to higher levels of Ni than Co (Ni (mg/m³) = −0.02 + 7.41 Co (mg/m³), r = 0.979, P < 0.0001). Thus, exposure to Co at 0.1 mg/m³ should produce a Ni level of 0.7 mg/m³. According to section XIII of the German list of MAK and BAT Values, a relationship between exposure to Co and urinary Co excretion, Co (μg/l) = 600 Co (mg/m³), has been established and the relationship between soluble or insoluble Ni salts in the air and Ni in urine was as follows: Ni (μg/l) = 10 + 600 Ni (mg/m³) or Ni (μg/l) = 7.5 + 75 Ni (mg/m³). Assuming nickel hydroxide to be soluble and to be insoluble, the Ni concentrations corresponding to Ni exposure at 0.7 mg/m³ were calculated as 430 and 60 μg Ni/l, respectively. Similarly, exposure to Co at 0.1 mg/m³ should result in Co urinary concentrations of 60 μg Co/l. On the other hand, a good correlation was found between Co and Ni in post-shift urine (Ni (μg/l) = 9.9 + 0.343 Co (μg/l), r = 0.833, P < 0.0001). On the basis of this relationship, the corresponding value found in our study was 0.343 × 60 μg Co/l + 9.9 = 30.5 μg Ni/l. This value was close to that calculated by the equation for a group of insoluble compounds, but about 14 times lower than that calculated by the equation for a group of soluble compounds. Conclusions Our results suggest that exposure to nickel hydroxide yields lower urine nickel concentrations than the very soluble nickel salts, and that the grouping of nickel hydroxide might be reevaluated. Therefore, to evaluate conclusively the relationship between nickel hydroxide dust in the air and Ni in post-shift urine, further studies are necessary.     

Occupational exposure to airborne mercury during gold mining operations near El Callao, Venezuela

Objective: The National Institute for Occupational Safety and Health (NIOSH) recently conducted a cross–sectional study during gold mining operations near El Callao, Venezuela. The purpose of the study was to assess mercury exposures and mercury-related microdamage to the kidneys. The study consisted of concurrent occupational hygiene and biological monitoring, and an examination of the processing techniques employed at the different mining facilities. Mercury was used in these facilities to remove gold by forming a mercury-gold amalgam. The gold was purified either by heating the amalgam in the open with a propane torch or by using a small retort. Methods: Thirty-eight workers participated in this study. Some participants were employed by a large mining company, while others were considered “informal miners” (self-employed). Mercury exposure was monitored by sampling air from the workers' breathing zones. These full-shift air samples were used to calculate time-weighted average (TWA) mercury exposure concentrations. A questionnaire was administered and a spot urine sample was collected. Each urine sample was analyzed for mercury, creatinine, and N-acetyl-ß-d-glucosaminidase (NAG). Results: The range for the 8-h TWA airborne mercury exposure concentrations was 0.1 to 6,315?μg/m³, with a mean of 183?μg/m³. Twenty percent of the TWA airborne mercury exposure measurements were above the NIOSH recommended exposure limit (REL) of 50?μg/m³, and 26% exceeded the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV) of 25?μg/m³. The mean urine mercury concentration was 101?μg/g creatinine (μg/g-Cr), and the data ranged from 2.5 to 912?μg/g-Cr. Forty–two percent of the study participants had urine mercury concentrations that exceeded the ACGIH biological exposure index (BEI) of 35?μg/g-Cr. Urinary NAG excretion is considered a biological marker of preclinical, nonspecific microdamage to the kidney's proximal tubule cells. The mean urine NAG concentration was 3.6 International Units/g-Cr (IU/g-Cr) with a range of 0.5 to 11.5?IU/g-Cr. Three workers had urine NAG levels in excess of the reference values. Correlation analyses found statistically significant correlations between airborne mercury exposure and urine mercury level (P=0.01), and between urine mercury level and urine NAG excretion (P=0.01). In addition, the airborne mercury exposure data and urine mercury data were segregated by job tasks. A Wilcoxon rank sum test revealed significant correlations between tasks and mercury exposure (P=0.03), and between tasks and urine mercury level (P=0.02). Conclusions: The tasks with the highest mean airborne mercury exposures were “burning the mercury-gold amalgam” and “gold refining/smelting”. Recommendations were provided for improving the retort design to better contain mercury, for ventilation in the gold shops, and for medical surveillance and educational programs.     

Trends and patterns of air quality in Santa Cruz de Tenerife (Canary Islands) in the period 2011–2015

Air quality trends and patterns in the coastal city of Santa Cruz de Tenerife (Canary Islands, Spain) for the period 2011–2015 were analyzed. The orographic and meteorological characteristics, the proximity to the African continent, and the influence of the Azores anticyclone in combination with the anthropogenic (oil refinery, road/maritime traffic) and natural emissions create specific dispersion conditions. SO₂, NO₂, PM₁₀, PM_2.5, and O₃ pollutants were assessed. The refinery was the primary source of SO₂; EU hourly and daily average limit values were exceeded during 2011 and alert thresholds were reached in 2011 and 2012. WHO daily mean guideline was occasionally exceeded. Annual averages in the three stations that registered the highest concentrations in 2011 and 2012 were between 9.3 and 20.4 μg/m³. The spatial analysis of SO₂ concentrations with respect to prevailing winds corroborates a clear influence of the refinery to the SO₂ levels. In 2014 and 2015, the refinery did not operate and the concentrations fell abruptly to background levels of 2.5–7.1 μg/m³ far below from WHO AQG. NO₂ EU limit values, as well as WHO AQG for the period 2011–2015, were not exceeded. The progressive dieselization of the vehicle fleet caused an increment on NO₂ annual mean concentrations (from 2011 to 2015) measured at two stations close to busy roads 25 to 31 μg/m³ (+21%) and 27 to 35 μg/m³ (+29%). NO _x daily and weekly cycles (working days and weekends) were characterized. An anti-correlation was found between NO _x and O₃, showing that O₃ is titrated by locally emitted NO. Higher O₃ concentrations were reported because less NO _x emitted during the weekends showing a clear weekend effect. Saharan dust intrusions have a significant impact on PM levels. After subtracting natural sources contribution, none of the stations reached the EU maximum 35 yearly exceedances of daily means despite seldom exceedances at some stations. None of the stations exceeded the annual mean EU limit values; however, many stations exceeded the annual mean WHO AQG. Observed PM₁₀ annual average concentrations in all the stations fluctuated between 10.1 and 35.3 μg/m³, where background concentrations were 6.5–24.4 μg/m³ and natural contributions: 4.2–9.1 μg/m³. No PM₁₀ temporal trends were identified during the period except for an effect of washout due to the rain: concentrations were lower in 2013 and 2014 (the most rainy years of the period). None of the stations reached the PM_2.5 annual mean EU 2015 limit value. However, almost all the stations registered daily mean WHO AQG exceedances. During 2015, PM_2.5 concentrations were higher than the previous years (2015, 8.8–12.3 μg/m³; 2011–2014, 3.7–9.6 μg/m³). O₃ complied with EU target values; stricter WHO AQG were sometimes exceeded in all the stations for the whole time period.     

Serum and urinary aluminium levels of workers in the aluminium industry

We have measured serum aluminium and urinary aluminium/creatinine ratios in 235 aluminium workers and 44 controls to examine the association between occupational exposure to airborne aluminium and aluminium absorption. Serum and urine samples were taken before and after a 3- to 5-day work shift. Occupational exposure was estimated from aluminium measurements of respirable and total particulates in air. Median exposure values were 25 and 100 μg m⁻³, respectively. Serum aluminium and urinary aluminium/creatinine ratios did not change significantly during the shift; however, both pre-shift and post-shift serum aluminium and urinary aluminium/creatinine ratios were increased in the exposed group. Occupational exposure was associated with serum aluminium increments of 1.32μg l.⁻¹ (P = 0.01) pre-shift, and 0.96μg l.⁻¹ (P = 0.08) post-shift. Greater and more significant differences were seen between exposed and controls for the urinary aluminium/creatinine ratios [5.67 μg g⁻¹ (P < 0.01) pre-shift; 8.01 μg g⁻¹ (P < 0.01) post-shift]. Urinary aluminium/creatinine ratios were greater in plants with higher aluminium exposures. These results are consistent with the systemic absorption of aluminium from occupational exposure and suggest the presence of a sensitive uptake process for airway aluminium.     

Reduction in welding fume and metal exposure of stainless steel welders: an example from the WELDOX study

Purpose

In a plant where flux-cored arc welding was applied to stainless steel, we investigated changes in airborne and internal metal exposure following improvements of exhaust ventilation and respiratory protection.

Methods

Twelve welders were examined at a time in 2008 and in 2011 after improving health protection. Seven welders were enrolled in both surveys. Exposure measurement was performed by personal sampling of respirable welding fume inside the welding helmets during one work shift. Urine and blood samples were taken after the shift. Chromium (Cr), nickel (Ni), and manganese (Mn) were determined in air and biological samples.

Results

The geometric mean of respirable particles could be reduced from 4.1 mg/m³ in 2008–0.5 mg/m³ in 2011. Exposure to airborne metal compounds was also strongly reduced (Mn: 399 vs. 6.8 μg/m³; Cr: 187 vs. 6.3 μg/m³; Ni: 76 vs. 2.8 μg/m³), with the most striking reduction inside helmets with purified air supply. Area sampling revealed several concentrations above established or proposed exposure limits. Urinary metal concentrations were also reduced, but to a lesser extent (Cr: 14.8 vs. 4.5 μg/L; Ni: 7.9 vs. 3.1 μg/L). Although biologically regulated, the mean Mn concentration in blood declined from 12.8 to 8.9 μg/L.

Conclusion

This intervention study demonstrated a distinct reduction in the exposure of welders using improved exhaust ventilation and welding helmets with purified air supply in the daily routine. Data from area sampling and biomonitoring indicated that the area background level may add considerably to the internal exposure.     

Determination of nickel in lung specimens of thirty-nine autopsied nickel workers

Summary Lung specimens from 39 nickel refinery workers autopsied during the period from 1978 to 1984 were analyzed for nickel. Fifteen of the workers were employed in the Roasting and Smelting Department, where exposure to nickel was predominantly in the form of nickel-copper oxides, Ni₃S₂ and metallic dust. The remaining 24 men worked in the Electrolysis Department. Exposure in this group was considered to be mostly to the water-soluble compounds, NiSO₄ and NiCl₂, but also to a lesser degree to water-insoluble nickel compounds such as nickel-copper oxides and sulphides. The arithmetic mean ± SD for nickel concentration in lung tissues expressed in gg^–1 dry wt for the 39 workers was 150 ± 280. In the workers employed in the Roasting and Smelting Department, the average nickel concentration was 330 ± 380; for those who worked in the Electrolysis Department it was 34 ± 48. Lung tissue from 16 autopsied persons not connected with the refinery had an average nickel concentration of 0.76 ± 0.39. Statistical analysis based on log-normal distributions of the measured nickel concentrations allowed three major conclusions to be formulated: (1) nickel refinery workers exhibit elevated nickel levels in lung tissues at autopsy; (2) workers of the Electrolysis Department and the Roasting Smelting Department constitute distinct groups with respect to the accumulation of nickel in lung tissue; (3) workers who were diagnosed to have lung cancer had the same lung nickel concentrations at autopsy as those who died of other causes.     

Update of cancer incidence among workers at a copper/nickel smelter and nickel refinery

Objectives: To assess cancer risk among nickel-exposed workers. Methods: We updated cancer incidence among 1388 workers employed for at least 3 months at a copper/nickel smelter and nickel refinery in Harjavalta, Finland. There were 1155 workers exposed to nickel during the period 1960–1985 in the smelter (566 workers), repair shop (239 workers), or refinery (418 workers). Cancer incidence was followed through the files of the Finnish Cancer Registry up to 31 December 1995. For overall cancer and for a priori selected specific cancer types the ratio of observed to expected numbers of cases was computed as a standardized incidence ratio (SIR), controlled for age, gender, and calendar period and using the region-specific rates as a reference. Results: The overall cancer incidence among both nickel-exposed and unexposed subcohorts was at the expected level. A small increase in lung cancer incidence, which reached statistical significance among workers with a latency exceeding 20 years, was observed among the smelter workers exposed to insoluble nickel compounds. Among workers in the refinery, who were exposed primarily to nickel sulfate at levels below 0.5 mg/m³ as well as to low concentrations of other nickel compounds, there was an increased risk for nasal cancer (SIR 41.1, 95% CI 4.97–148), positively associated with latency and duration of employment, and an excess risk for stomach (SIR 4.98, 95% CI 1.62–11.6) and lung (SIR 2.61, 95% CI 0.96–5.67) cancers. Conclusions: Since elevated nasal and lung cancer risks were confined to the refinery, where the primary exposure was to nickel sulfate, it is likely that nickel sulfate is mainly responsible for the elevated respiratory cancer risk. We cannot rule out whether the excess stomach cancer risk is a chance finding, or related to the working environment. Received: 11 September 1997 / Accepted: 17 October 1997     

Distribution of nickel in lungs from former nickel workers

Objective: The purpose of this work was to study the distribution of nickel within lung tissue obtained from nickel-exposed people and to evaluate the␣use of only one single sample for determination of the nickel burden of the lung. Methods and materials: The material used was lung tissue obtained from 15 former nickel refinery workers who had been exposed to a variety of nickel compounds such as Ni₃S₂, NiO, Ni⁰, NiSO₄, and NiCl₂. Ten samples taken from different locations of the lung as well as from the right and left bronchus and from the right lower lobe (total 13 samples per individual) were analyzed for nickel by electrothermal atomic absorption spectrometry. Samples obtained from ten people not connected to the refinery served as a reference group. Results: The arithmetic mean value ± SD for nickel concentration was 50 ± 150 μg g⁻¹ dry wt. Biopsies collected on the center of the lower right lobe had an average nickel concentration of 82 ± 252 μg g⁻¹. The average nickel concentration detected in the right and left bronchus was 5.9 ± 11.6 and 3.8 ± 6.0 μg g⁻¹, respectively. Lung tissue obtained from ten people not connected to the refinery had an average nickel concentration of 0.74 ± 0.44 μg g⁻¹. Conclusions: The significant findings based on log-normal distribution of the nickel concentration were as follows: (1) samples obtained from the right lung showed no significant difference from samples taken from the left lung–a comparison of the nickel concentration detected in all the lung lobes showed that no single lobe differed from another; (2) the concentration of nickel found in the main bronchus of the refinery workers, although elevated, was significantly lower than the concentration detected in the remaining tissue; and (3) one single biopsy did not reflect the nickel burden of the lung. Received: 20 November 1997 / Accepted: 21 April 1998     

Exposure assessment in the hard metal manufacturing industry with special regard to tungsten and its compounds

OBJECTIVES—To assess the exposure to tungsten, cobalt, and nickel in a plant producing hard metals. The main components of hard metals are tungsten carbide and cobalt metal. According to recent studies, these two components may be responsible for both fibrogenic and carcinogenic effects.
METHODS—87 workers were investigated (86 male, one female) with a median age of 42 (range 22-58) and a mean duration of exposure of 13 years (range 1-27 years). Stationary and personal air sampling, and biological monitoring were carried out.
RESULTS—Ambient monitoring yielded maximum tungsten concentrations of 417 µg/m³ in the production of heavy alloys. A maximum cobalt concentration of 343 µg/m³ and a maximum nickel concentration of 30 µg/m³ were found at the sintering workshop. The highest urinary cobalt concentrations were found in the powder processing department. The mean concentration was 28.5 µg/g creatinine and the maximum value was 228 µg/g creatinine. The maximum nickel concentration in urine of 6.3 µg/g creatinine was detected in the department producing heavy alloys. The highest tungsten concentrations excreted in urine were found in grinders and had a mean value of 94.4 µg/g creatinine and a maximum of 169 µg/g creatinine. Due to the different solubility and bioavailability of the substance, there was no correlation between the tungsten concentrations in air and urine on a group basis.
CONCLUSIONS—Despite its low solubility, tungsten carbide is bioavailable. The different bioavailability of tungsten metal and tungsten compounds has to be considered in the interpretation of ambient and biological monitoring data in the hard metal producing industry. The bioavailability increases in the order: tungsten metal, tungsten carbide, tungstenate. Only if both monitoring strategies are considered in combination can a valid and effective definition of high risk groups be derived.


Keywords: tungsten; cobalt; biological monitoring     

Prevalence of nickel sensitization and urinary nickel content of children are increased by nickel in ambient air

In a cross-sectional study performed in 2000, an unexpected positive association between nickel (Ni) in ambient air, urinary Ni content and the prevalence of Ni sensitization in a subgroup of 6-yr-old children living near a steel mill was observed. Between 2005 and 2006, in a different and larger study population, we examined if Ni from ambient air or urinary Ni concentration was related to Ni sensitization in children living next to Ni-emitting steel mills.We studied 749 school beginners living in four Ni-polluted industrial areas of North Rhine-Westphalia, Germany. We assessed Ni in ambient air, Ni in urine from children and mothers, and Ni in tap water, conducted patch tests in children (including the NiSO₄-dilution test) and collected questionnaire data. Statistics were done by linear and logistic regression analyses, adjusted for covariates.At increased Ni concentration in ambient air (unit of increase: 10 ng/m³), urinary Ni concentrations rose in both mothers (9.1%; 95% CI: 6.8–11.4%) and children (2.4%; 95% CI: 0.4–4.4%). The prevalence of Ni sensitization in children was associated with increased Ni from ambient air (unit of increase: 18 ng/m³; odds ratio 1.28; 95% CI: 1.25–1.32) and urinary Ni concentration (unit of increase: 7.1 μg/L; odds ratio 2.4; 95% CI: 1.20–4.48). Ni in ambient air of areas with Ni-emitting factories contributes to internal Ni exposure in residents via inhalation and, furthermore, is a risk factor for the development of Ni sensitization in children.     

Second-hand smoke in hospitals in Catalonia (2009): a cross-sectional study measuring PM2.5 and vapor-phase nicotine

ObjectivesTo describe second-hand smoke in the hospitals of the Catalan Network for Smoke-free Hospitals using Particulate Matter (PM_2.5) and to assess the association between second-hand smoke exposure in main entrances (outdoors) and halls and between PM_2.5 and airborne nicotine concentrations.MethodsCross-sectional study carried out in 2009 in the 53 hospitals affiliated with the network. We measured PM_2.5 (μg/m³) in all hospitals and measured airborne nicotine concentrations (μg/m³) in a subsample of 11 hospitals. For each assessment, we measured nine locations within the hospitals, computing medians, means, geometric means, interquartile ranges (IQRs), and 95% confidence intervals (CI) of the means and the geometric means. Further, we used Spearman’s linear correlation coefficient r_sp) to explore the association between PM_2.5 concentrations in halls and main entrances and between PM_2.5 and nicotine concentrations.ResultsThe overall median of the 429 PM_2.5 measurements was 12.48 μg/m³ (IQR: 8.84–19.76 μg/m³). The most exposed locations were outdoor smoking points (16.64 μg/m³), cafeterias (14.82 μg/m³), and main entrances (14.04 μg/m³); dressing rooms were the least exposed (6.76 μg/m³). PM_2.5 concentrations in halls were positively correlated with those in main entrances (r_sp=0.591, 95% CI: 0.377–0.745), as were PM_2.5 values and nicotine concentrations (r_sp=0.644, 95% CI: 0.357–0.820).ConclusionsSecond-hand smoke levels in hospitals were low in most locations, with the highest levels observed in outdoor locations where smoking is allowed (smoking points and entrances). Smoking in main entrances was associated with increased second-hand smoke levels in halls. Use of PM_2.5 to evaluate second-hand smoke is feasible and shows a good correlation with airborne nicotine values.     

Occupational exposure to particulate matter and endotoxin for California dairy workers

Occupational exposure of dairy workers to particulate matter (PM) and endotoxin has been considered by some to be of potential concern. This paper reports personal exposure concentrations of PM (μg/m³) and endotoxin (EU/m³) for 226 workers from 13 California dairies. Arithmetic mean personal concentrations for PM_2.5, inhalable PM and endotoxin were 48 μg/m³ (N = 222), 987 μg/m³ (N = 225) and 453 EU/m³ (N = 225), respectively. Using mixed effects models, time spent re-bedding of freestall barns versus any other job conducted on a dairy led to the highest exposure for PM_2.5, inhalable PM, and endotoxin. Personal exposure concentrations were found to be greater than those reported for ambient area based concentrations at the same dairies. A pseudo R-square approach revealed that one area based measure combined with time spent performing tasks explained a significant portion of variation in personal exposure concentrations.     

Occupational chronic exposure to metals

Summary Stainless steel welders (n = 103) were examined. To estimate external exposure, personal air sampling was used. Internal exposure was quantified by the determination of nickel levels in erythrocytes, plasma and urine. Men and women (n = 123) were examined for control purposes. In the plasma and erythrocytes of the controls the nickel concentration was below the level of detection (< 1.81 μg/l). The element concentrations in urine were between < 0.1 and 13.3 μg/l. Of the controls 95% showed nickel levels in urine below 2.2 μg/l (reference value). The average concentration of nickel in the air was 93 ± 81 μg/m³. The average concentration of nickel in the plasma samples was 4.9 ± 4.0 μg/l (95th percentile 12.8 μg/L). In erythrocytes nickel could not be detected. The nickel concentrations in the urine of the welders were 18.5 ± 28.5 μg/l on average (95th percentile 52.5 μg/l). Only a weak correlation between the nickel levels of plasma and urine could be detected (C_urine = 2.07 + 8.45 C_plasma; r = 0.294; p < 0.01). Based on our results and on the reported literature a future limit value for the nickel concentration in urine should lay between 30 and 50 μg/l. This value corresponds to an external exposure of 500 μg nickel per cubic metre.     

Exposure to dust,endotoxin and micro-organisms in the potato processing industry

Exposure to organic dust components was studied in four potato processing plants because preliminary results showed high exposures accompanied by work-related health complaints. Ambient air concentrations of inhalable dust ranged from below 0.4 up to 44 mg m⁻³ [geometric mean (GM) 0.64 mg m⁻³]. Respirable dust concentrations were considerably lower. Personal concentrations of inhalable dust were somewhat higher, and strongly related to a few working tasks dealing with dried starch or protein. Ambient air concentrations of endotoxin ranged from 0.5 to more than 60 000 endotoxin units (EU) per m³ for the inhalable size fraction (GM = 280 EU m⁻³). For the respirable size fraction, endotoxin concentrations were lower (about the same factor as for dust). Personal endotoxin concentrations were lower than ambient air concentrations, probably because workers did not work the whole period of the shift near endotoxin sources. Endotoxin exposure was evaluated as very high; 23% of the workers had a mean exposure above 1000 EU m⁻³ (100 ng m⁻³). Differences between plants had a large influence on both dust and endotoxin exposure. A fairly good correlation was found between counts of airborne gram-negative bacteria and airborne endotoxin of the respirable size fraction. Ambient air levels of bacteria and endotoxin were strongly related to process water temperature, suggesting that exposure reduction can be achieved by lowering this temperature or by other measures that inhibit bacterial growth. We conclude that recycling of process water probably constitutes an exposure source of bacteria and endotoxin in many facilities.     

Levels and sources of volatile organic compounds including carbonyls in indoor air of homes of Puertollano,the most industrialized city in central Iberian Peninsula. Estimation of health risk

Twenty nine organic air pollutants including carbonyl compounds, alkanes, aromatic hydrocarbons and terpenes were measured in the indoor environment of different houses together with the corresponding outdoor measurements in Puertollano, the most industrialized city in central Iberian Peninsula. VOCs were sampled during 8 weeks using Radiello^® passive samplers, and a questionnaire on potential VOCs sources was filled out by the occupants. The results show that formaldehyde and hexanal was the most abundant VOCs measured in indoor air, with a median concentration of 55.5 and 46.4 μg m⁻³, respectively followed by butanal (29.1 μg m⁻³), acetone (28.4 μg m⁻³) and acetaldehyde (21.4 μg m⁻³). After carbonyls, n-dodecane (13.1 μg m⁻³) and terpenes (α-pinene, 13.4 μg m⁻³ and limonene, 13.4 μg m⁻³) were the compounds with higher median concentrations. The indoor/outdoor (I/O) ratios demonstrated that sources in the indoor environment are prevailing for most of the investigated VOCs especially for limonene, α-pinene, hexanal, formaldehyde, pentanal, acetaldehyde, o-xylene, n-dodecane and acetone with I/O ratio >6. Multiple linear regressions were applied to investigate the indoor VOC determinants and Spearman correlation coefficients were used to establish common sources between VOCs. Finally, the lifetime cancer risk associated to formaldehyde, acetaldehyde and benzene exposure was estimated and they varied from 7.8 × 10⁻⁵ to 4.1 × 10⁻⁴ for formaldehyde, from 8.6 × 10⁻⁶ to 3.5 × 10⁻⁵ for acetaldehyde and from 2.0 × 10⁻⁶ to 1.5 × 10⁻⁵ for benzene. For formaldehyde, the attributed risk in most sampled homes was two orders of magnitude higher than the one (10⁻⁶) proposed as acceptable by risk management bodies.     

Passive exposure to pollutants from conventional cigarettes and new electronic smoking devices (IQOS,e-cigarette) in passenger cars

Smoking in car interiors is of particular concern because concentrations of potentially harmful substances can be expected to be high in such small spaces. To assess the potential exposure for occupants, especially children, we performed a comprehensive evaluation of the pollution in 7 passenger cars while tobacco cigarettes and new electronic smoking products (IQOS, e-cigarette) were being smoked. We collected data on the indoor climate and indoor air pollution with fine and ultrafine particles and volatile organic compounds while the cars were being driven. Smoking of an IQOS had almost no effect on the mean number concentration (NC) of fine particles (>300?nm) or on the PM_2.5 concentration in the interior. In contrast, the NC of particles with a diameter of 25–300?nm markedly increased in all vehicles (1.6–12.3?×?10⁴/cm³). When an e-cigarette was vaped in the interior, 5 of the 7 tested cars showed a strong increase in the PM_2.5 concentration to 75–490?μg/m³. The highest PM_2.5 levels (64-1988?μg/m³) were measured while tobacco cigarettes were being smoked. With the e-cigarette, the concentration of propylene glycol increased in 5 car interiors to 50–762?μg/m³, whereby the German indoor health precaution guide value for propylene glycol was exceeded in 3 vehicles and the health hazard guide value in one. In 4 vehicles, the nicotine concentration also increased to 4–10?μg/m³ while the e-cigarette was being used. The nicotine concentrations associated with the IQOS and e-cigarette were comparable, whereas the highest nicotine levels (8–140?μg/m³) were reached with tobacco cigarettes. Cigarette use also led to pollution of the room air with formaldehyde (18.5–56.5?μg/m³), acetaldehyde (26.5–141.5?μg/m³), and acetone (27.8–75.8?μg/m³). Tobacco cigarettes, e-cigarettes, and the IQOS are all avoidable sources of indoor pollutants. To protect the health of other non-smoking passengers, especially that of sensitive individuals such as children and pregnant women, these products should not be used in cars.     

Biologic monitoring of chromium and nickel among stainless steel welders using the manual metal arc method

Summary Forty manual metal arc welders welding stainless steel (SS) were monitored for 1–7 workdays measuring total chromium (Cr), water-soluble hexavalent Cr^VI, and nickel (Ni) in the working atmosphere, and Cr and Ni in blood and urine. The mean daily increase was 1.0 g Cr/l in plasma and 5.6 g Cr/g creatinine in urine. There were significant correlations between total Cr and Cr^VI in air and the total Cr in biologic fluids. This was not the case for the corresponding correlations for Ni. The observed correlations between urinary and plasma Cr levels may permit interchange of these body fluids for biologic monitoring at high exposures. The results indicate that urine sampled after work is a body fluid versatile for routine monitoring of Cr in SS welders. Smokers had higher levels of Cr in biologic fluids than did nonsmokers at equivalent levels of air Cr^VI. The results also indicate that filter masks provide better protection against uptake of Cr in the airways than air-stream helmets.Deceased 6 October 1987     

Monitoring of chromium and nickel in biological fluids of grinders grinding stainless steel

Objective Stainless steel (SS) welders usually spend some of their working time grinding, to finish and smoothen the welding groove. The aim of this study was to investigate possible relations between the concentrations of nickel (Ni) and chromium (Cr) in the work atmosphere generated by grinders grinding SS, and to compare the air levels to the levels of Cr and Ni in their biological fluids. Hereby, it might be possible to identify the contribution of grinding to the levels of Cr and Ni in biological fluids in SS welders. Also the airborne levels of Cr and Ni in SS grinders were compared to corresponding levels in SS welders. Method/design The subjects examined in this study were selected among SS grinders not performing welding. Nine grinders were monitored for 1 workweek, measuring Cr and Ni in air, blood and urine. They were questioned about their exposure to Cr and Ni during their working careers. Results Air levels of total Cr up to 95 μg/m³ and Ni levels up to 25 μg/m³ were measured. Chromium^VI (Cr^VI) was detectable only in five air samples; the levels in the remaining samples were below the detection limit. The levels of Cr in blood and urine were also low. The levels of Ni in urine were close to those for MMA and MIG/MAG SS welders. In spite of high levels of total Cr and Ni observed in air, the levels found in biological fluids were low. The Cr levels in more than 50% of the whole blood and red cell samples and about 1/3 of the Cr–plasma levels were below the detection limits. The mean blood levels for Cr were 0.43, 0.60 and 0.35 μg/l, in whole blood, plasma and red cells, respectively. The mean levels for Cr in the urine was 1.6, 1.4 and 1.4 μg/g creatinine for the first void, just before and just after work. For Ni the mean blood levels were 0.87 μg/l in whole blood and 0.68 μg/l in plasma. The mean levels and ranges of Ni from the first void, just before and after work in urine were 3.79 μg/g creatinine, 3.39 and 4.56, respectively. The Cr concentrations found in whole blood, plasma and red cells were approximately the same as those found in the unexposed controls and among TIG SS welders, while the urinary levels were somewhat higher, but still lower than in the welders applying other welding techniques. The mean levels of Ni in the urine of grinders were higher than those of welders, except for SS welders welding the MIG/MAG-method. Conclusion SS Grinding seems not to contribute significantly to the uptake of Cr, which may be explained by the fact that most of Cr in the air is present in the metallic (0-valent) or trivalent form, and hardly any as Cr^VI, and therefore hardly being taken up in the airways. The grinders’ uptake of Ni seems to take place to the same extent as in SS welders.