Vaccination-induced HI antibody response to intraepidemic influenza A(H3N2) virus variants of the 1996-1997 epidemic season.

Intraepidemic antigenic and genetic variation was indicated when H3N2-subtype influenza A virus strains isolated during the 1996-1997 epidemic season in Finland were studied for reactivity in the haemagglutination inhibition (HI) assay and for nucleotide sequences coding for the variable HA1 domain of viral haemagglutinin. Thirty prevaccination- and postvaccination-paired sera taken from subjects who had been vaccinated against influenza during the previous autumn were studied for the presence of HI antibody to the homologous vaccine virus A/Nanchang/933/95, and five field strains representing the genetic and antigenic variability of the 1996-1997 epidemic season. The lowest vaccination-induced HI titres in each of the three age groups were detected in the two field strains that had been isolated from vaccinated patients and belonged to two different genetic sublineages. The intraepidemic variability of the 1996-1997 field strains in HI reactivity may be indicative of circulation of virus strains that may be capable of breaking through vaccination-induced immunity better than the other strains.

Characterization and control of terpene emissions in Finnish sawmills.

This article describes an experimental study of terpene emission rates during fresh pine and spruce sawing and processing. Total terpene emission was determined by summing the product of the exhaust airflow rate and the mean concentration in the exhaust. Terpene concentrations were measured at fixed sampling points between the sawing lines. Terpene emission during pine sawing was found to be around 10 times greater than that during spruce sawing. The emission rates given here can be used to predict emission rates for various production rates. The predicted emission rates can be used in mass balance models to predict concentrations or required airflow rates to achieve the target concentration level.

Predictive validity of symptoms and signs in the neck and shoulders.

A standardized examination protocol was developed for the assessment of neck and shoulder disorders in primary health care. We investigated to what extent the symptoms and signs can predict sick leave due to neck and shoulder disorders. Our study involved 474 patients seeking medical advice from an occupational health service. Most of the 20 symptoms and 15 signs of the protocol were associated with the number of sick leave days within the 60-day postexamination period, but only three symptoms (short duration, high pain intensity, and continuous pain) and two signs (pain in the upper limb during rotation of head and pain in the shoulder during abduction of arm) retained their significance in a multivariate model. No unambiguous subset of protocol items can be suggested for general use. The predictive validity should be tested in other populations and settings before a conclusion is drawn about the external validity of the results.

Exposure of workers to 2,3,7,8-substituted polychlorinated dibenzo-p-dioxin (PCDD) and dibenzofuran (PCDF) compounds in sawmills previously using chlorophenol-containing antistain agents.

The use of chlorophenol-containing antistain agents (e.g., Ky5, a wood preservative) ceased in Finland at the end of the 1980s, after 5 decades of use. Exposure of workers to the impurities in these agents (i.e., polychlorinated dibenzo-p-dioxins [PCDDs] and dibenzofurans [PCDFs]) was assessed at three sawmills at which personnel used a sodium chlorophenate product as an antistain agent. Given that compounds accumulate in body fat and their half-lives in humans are long, we could determine 2,3,7,8-substituted PCDDs and PCDFs 5-9 y after the last exposure occurred. We used high-resolution gas chromatography/high-resolution mass spectrometry to determine PCDDs/PCDFs in plasma from 39 Ky5-exposed workers and 18 nonexposed workers. The average total plasma concentration of PCDD/PCDF of the Ky5-exposed workers at the three sawmills were 1018, 945, and 1165 pg/g fat, and corresponding concentrations in the nonexposed workers were 743, 1124, and 844 pg/g fat, respectively. We found no significant differences in total levels between Ky5-exposed workers and nonexposed workers. However, concentrations of the 1,2,3,4,6,7,8-HpCDF isomer were significantly higher (p < .01) among the Ky5-exposed workers at all three sawmills (averages of 224, 99, and 148 pg/g fat) than among their respective nonexposed workers (averages of 43, 48, and 44 pg/g fat). These results indicate that workers had handled Ky5. When we expressed concentration levels in international toxic equivalents (I-TEQs), the mean total I-TEQ PCDD/PCDF of Ky5-exposed workers was significantly lower at one of the sawmills (average = 42 pg I-TEQ/g) than at the other two sawmills (averages of 64 and 62 pg I-TEQ/g)(p < .05). Nevertheless, total concentrations at the sawmills studied were within the range of background levels in the general population.

Standardized physical examination protocol for low back disorders: feasibility of use and validity of symptoms and signs.

A standardized examination protocol was developed for the assessment of low back disorders in primary care. The protocol was found feasible in the occupational health service setting. The interexaminer repeatability between an occupational physician and an occupational physiotherapist was good for most items. The predictive validity of different symptoms and signs was investigated with regard to future sick leaves due to low back disorders. Relief of pain when lying, severe trouble at work caused by pain, continuous pain, and pain in the leg or numbness or diminished sensitivity in the foot predicted sick leaves. Of physical signs, pain in the low back or buttock during lateral flexion and a side difference > or = 20 degrees in the straight-leg-raising angle were predictors for sick leaves. The predictive validity of the protocol items should be tested in another patient population before conclusions can be drawn concerning the external validity of our results.

Cytogenetic effects of softwood kraft pulp bleaching effluents and methanesulfonyl chloride in Chinese hamster ovary cells.

The genotoxicity of effluents collected from a conventional 5-stage softwood kraft pulp bleaching process was studied in Chinese hamster ovary (CHO) cells in vitro. Spent liquor from the first chlorination stage (C/D), where elemental chlorine and chlorine dioxide had been used in equal proportions, was shown to induce a dose-dependent increase in sister chromatid exchanges (SCEs) without metabolic activation (4-h treatment), with a maximum increase of 1.6 times over the control level at 204 microliters/ml; this dose also induced 15.5- and 20.5-fold increases in cells with chromatid-type chromosomal aberrations after 4-h and a 20-h treatment, respectively. Another C/D stage spent liquor from a process where the ratio of elemental chlorine and chlorine dioxide had been 9:1 produced a 40.5-fold elevation of cells with chromatid-type aberrations at 204 microliters/ml (20-h treatment). This sample clearly increased chromosomal aberrations also when tested as a concentrate (4-h treatment), which showed that the observed clastogenicity was not unspecifically due to the relatively large volumes used in the treatments with the unconcentrated liquors. In general, the use of rat liver S9 mix reduced the genotoxicity of the spent liquors. The results agree with earlier findings on the Salmonella mutagenicity of the same C/D samples: both the prokaryotic and eukaryotic assays showed a reduction in genotoxicity when the amount of elemental chlorine in the bleaching process was reduced. An effluent sample collected from the alkaline stage of the process was not clastogenic with or without metabolic activation. Methanesulfonyl chloride, a new compound identified in bleaching plant air, was found to be induce chromosomal aberrations in the presence of S9 mix.

The South Karelia Air Pollution Study: effects of low-level exposure to malodorous sulfur compounds on symptoms.

Exposure to very low levels of ambient-air malodorous sulfur compounds and their effect on eye irritation, respiratory-tract symptoms, and central nervous system symptoms in adults were assessed. A cross-sectional self-administered questionnaire (response rate = 77%) was distributed during March and April 1992 to adults (n = 336) who lived in a neighborhood that contained a pulp mill and in a nonpolluted reference community (n = 380). In the exposed community, the measured annual mean concentrations of total reduced sulfur compounds and sulfur dioxide measured in two stations were 2 to 3 micrograms/m3 and 1 micrograms/m3, respectively. In the reference community, the annual mean concentration of sulfur dioxide was 1 micrograms/m3. The residents of the community near the pulp mill reported an excess of cough, respiratory infections, and headache during the previous 4 wk, as well as during the preceding 12 mo. The relative risk for headache was increased significantly in the exposed community, compared with the reference area: the adjusted odds ratio (aOR) was 1.83 (95% confidence interval [95% CI] = 1.06-3.15] during the previous 4 wk and 1.70 (95% CI = 1.05-2.73) during the preceding 12 mo. The relative risk for cough was also increased during the preceding 12 mo (aOR = 1.64, 95% CI = 1.01-2.64). These results indicated that adverse health effects of malodorous sulfur compounds occur at lower concentrations than reported previously.

PCDD/PCDF levels in the blood of workers at a pulp and paper mill.

Blood samples from 34 workers at a pulp and paper mill and from 14 control persons were analysed for 2,3,7,8-substituted PCDDs and PCDFs. There were no statistically significant differences in total lipid-adjusted PCDD/PCDF concentrations, expressed as toxic equivalents, in blood plasma between the potentially exposed bleaching plant or paper mill workers and the controls. The mean level was 61 pg/g I-TEQ in bleaching plant workers, 60 pg/g I-TEQ in paper mill workers and 49 I-TEQ pg/g in controls. Regarding the concentrations of individual isomers, however, there was an indication that the blood plasma concentrations might be affected by the living and working environment.

Gas chromatographic-mass spectrometric determination of chlorophenols in the urine of sawmill workers with past use of chlorophenol-containing anti-stain agents.

The aim of this work was to establish whether workers at sawmills where chlorophenol-containing anti-stain agents had been previously used were still exposed to chlorophenols. A gas chromatographic-mass spectrometric (GC-MS) procedure for the determination of chlorophenols in urine was developed. Chlorophenols were determined from hydrolysed urine as acetylated derivatives and determined by GC-MS using selected ion monitoring (SIM). Isolation of the chlorophenols with toluene gave the best extraction efficiencies (65-119%). Stability tests at -20 degrees C showed no degradation of the chlorophenols studied during 6 months. The limit of quantification was 3.6 ng mg-1 creatinine for 2,4,6-trichlorophenol, 5.5 ng mg-1 for 2,3,4,6-tetrachlorophenol and 3.6 ng mg-1 for pentachlorophenol. Traces of 2,4,6-trichlorophenol, 2,3,4,6-tetrachlorophenol and pentachlorophenol were found both in previously exposed workers and in non-exposed controls, the urinary concentrations ranging from 1.1 to 15.9 ng mg-1 creatinine. The concentrations of urinary chlorophenols in previously exposed workers were of the same magnitude as those found in non-exposed controls and in the general population. The results show that it is unlikely that sawmill workers would be currently occupationally exposed to chlorophenols or polychlorinated dibenzo-p-dioxins and dibenzofurans via a contaminated work environment.

The South Karelia Air Pollution Study: the effects of malodorous sulfur compounds from pulp mills on respiratory and other symptoms in children.

We assessed the role of long-term exposure to ambient air malodorous sulfur compounds released from pulp mills as a determinant of eye and respiratory symptoms and headache in children. Adverse health effects of environmental exposure to these compounds in children have not been reported previously. The parents of 134 children living in a severely polluted (n = 42), moderately polluted (n = 62) and rural nonpolluted (n = 30) community responded to a cross-sectional questionnaire. The response rate was 83%. The adjusted odds ratios (OR) for symptoms experienced during the previous 4 weeks and 12 months in the severely versus nonpolluted community were estimated in logistic regression analysis controlling for age and gender. The risk of nasal symptoms (4 weeks OR 1.40, 95% CI 0.59-3.31; 12 months OR 2.47, 95% CI 0.93-6.53), cough (4 weeks OR 1.83, 95% CI 0.75-4.45; 12 months OR 2.28, 95% CI 0.95-5.47), eye symptoms (12 months OR 1.15, 95% CI 0.43-3.05), and headache (12 months OR 1.77, 95% CI 0.69-4.54) was considerably increased in the severely polluted community, although not quite reaching statistical significance. The results suggest that exposure to malodorous sulfur compounds may affect the health of children.

Genotoxicity of kraft pulp spent liquors from different types of chlorination procedures.

The genotoxicity of spent liquors from kraft softwood and hardwood pulp bleaching processes was studied using the Ames Salmonella test and the SOS chromotest. The induction of micronuclei, in vivo, was assayed in bone marrow erythrocytes of B6 mice treated with softwood first chlorination stage spent liquor. The softwood bleaching process used a combination of Cl2 and ClO2 at the first chlorination stage. During the study the amount of free chlorine at the first chlorination stage in the softwood bleachery was gradually decreased, although the amount of active chlorine remained the same. Enzymatic bleaching was also used in a softwood process together with chlorine (Cl2 + ClO2). The hardwood bleaching plant used only ClO2 at the first chlorination stage. A decrease in genotoxicity, corresponding to the decrease in Cl2, was observed in the Ames Salmonella assays of the softwood bleaching plant effluents. A similar decrease was observed in the SOS chromotest. The highest decrease in mutagenic activity was observed when enzymatic bleaching was used together with chlorine.

Volatile metabolites in occupational exposure to organic sulfur compounds.

Dimethyl sulfide in breath was determined by the gas chromatographic method in 14 persons exposed to organic reduced sulfur compounds in sulfate pulp mills. Dimethyl sulfide concentrations in breath (range 0.04-0.69 cm3/m3 were compared to the combined workplace concentrations of methyl mercaptan, dimethyl sulfide and dimethyl disulfide. This method of analysis proved to be a practical noninvasive way to assess recent exposure, and therefore it should be applicable to workplaces contaminated with organic sulfur compounds in the pulp industry.

The South Karelia Air Pollution Study: acute health effects of malodorous sulfur air pollutants released by a pulp mill.

We evaluated the acute health effects of a strong emission of malodorous sulfur compounds released from a pulp mill in South Karelia, Finland. The 24-hour ambient air concentrations of hydrogen sulfide for the two emission days were 35 and 43 micrograms/m3 (maximum 4-hour 135 micrograms/m3). A questionnaire was distributed after the high exposure and later after a low exposure period to 29 households with 75 subjects living in the nearby community. During the high exposure, 63% of the respondents reported experience of at least one symptom compared to 26% during the reference period. Every third participant reported difficulties in breathing. In the 45 subjects responding to both questionnaires more eye, respiratory and neuropsychological symptoms occurred during the exposure compared to the reference period. The strong malodorous emission from a pulp mill caused an alarming amount of adverse effects in the exposed population.

Cancer incidence among pulp and paper workers exposed to organic chlorinated compounds formed during chlorine pulp bleaching.

The risk of cancer of 152 male workers exposed to organic chlorine compounds formed during chlorine pulp bleaching was assessed in a retrospective cohort study. The men had worked continuously for at least one year in selected job categories between 1 January 1945 and 31 December 1961. The cohort was followed for death and cancer incidence until 31 December 1987 with the use of the data of the National Population Register and the Finnish Cancer Registry. There were 12 observed cancers against 8.1 expected [standardized incidence ratio (SIR) 1.5, 95% confidence interval (95% CI) 0.8-2.6]. Among the stock preparation workers (N = 53), a significantly elevated risk of lung cancer was found (6 observed, 1.0 expected, SIR 6.3, 95% CI 2.3-14) that was especially prominent after a latency (time since first employment) of at least 15 years and in the age group of 35 to 59 years. Although all of the cases involved smokers, a part of the increased incidence may be associated with the workplace exposure to organic chlorinated compounds.

The South Karelia Air Pollution Study. The effects of malodorous sulfur compounds from pulp mills on respiratory and other symptoms.

The paper mills in South Karelia, the southeast part of Finland, are responsible for releasing a substantial amount of malodorous sulfur compounds such as hydrogen sulfide (H2S), methyl mercaptan (CH3SH), and methyl sulfides [(CH3)2S and (CH3)2S2], into ambient air. In the most polluted residential area the annual mean concentrations of hydrogen sulfide and methyl mercaptan are estimated to be 8 and 2 to 5 micrograms/m3 and the highest daily average concentration 100 and 50 micrograms/m3. The annual mean and highest daily concentrations of sulfur dioxide (SO2) are very low. We studied the effects of malodorous sulfur compounds on eye, nasal and respiratory symptoms, and headache in adults. A cross-sectional self-administered questionnaire was distributed in February 1987 and responded to by 488 adults living in a severely (n = 198), a moderately (n = 204), and a nonpolluted community (n = 86). This included questions about occurrence of the symptoms of interest during the previous 4 wk and 12 months and individual, behavioral, and other environmental determinants of the symptoms. The response rate was 83%. The odds ratios (OR) for symptoms experienced often or constantly in severely versus nonpolluted and moderately versus nonpolluted communities were estimated in logistic regression analysis controlling potential confounders. The odds ratios for eye (moderate exposure OR 11.70, Cl95% 2.33 to 58.65; severe exposure OR 11.78, Cl95% 2.35 to 59.09) and nasal symptoms (OR 2.01, Cl95% 0.97 to 4.15; OR 2.19, Cl95% 1.06 to 4.55) and cough (OR 1.89, Cl95% 0.61 to 5.86; OR 3.06, Cl95% 1.02 to 9.29) during the previous 12 months were increased, with a dose-response pattern.(ABSTRACT TRUNCATED AT 250 WORDS)

Exposure to hydrogen sulphide and respiratory function.

A study was carried out to assess possible effects of low concentrations of hydrogen sulphide on respiratory function. The cohort comprised 26 male pulp mill workers (mean age 40.3, range 22-60 years) with a daily exposure to hydrogen sulphide in the workplace, and 10 volunteers, who had asthma (three men, mean age 40.7, range 33 to 50 years, and seven women, mean age 44.1, range 31 to 61 years). The respiratory function of the pulp mill workers was monitored by measuring forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and bronchial responsiveness after at least one day off work and at the end of a workday. Bronchial responsiveness was tested by challenge with histamine. The 10 asthmatic subjects were exposed in laboratory conditions to 2 ppm of hydrogen sulphide for 30 minutes in an exposure chamber. Airway resistance (Raw) and specific airway conductance (SGaw) were assessed by a body plethysmograph, and the ventilatory capacities were measured with a flow volume spirometer. No significant changes in respiratory function or bronchial responsiveness related to exposure to hydrogen sulphide in the pulp mill workers were found. In the asthmatic subjects, Raw was increased by 26.3% and SGaw was decreased by 8.4% on average after exposure to hydrogen sulphide. These changes were not statistically significant. In two subjects, however, changes were greater than 30% in both Raw and SGaw, indicating bronchial obstruction. It is concluded that exposure for a relatively short time to hydrogen sulphide concentrations appreciably higher than those existing in ambient air do not cause noticeable effects on respiratory function.

Cardiovascular mortality among pulp mill workers.

A mortality study, concentrating on cardiovascular mortality, was undertaken among Finnish sulphite mill workers exposed to sulphur dioxide and sulphate mill workers exposed to hydrogen sulphide and organic sulphides. They had been employed continuously for at least one year between 1945 and 1961. National death rates were used for comparison and mortality was followed up until 31 December 1981. Among the cohort exposed to sulphur dioxide (2268 person-years), an excess of cardiovascular deaths was noticed among the men (24 obs, 19.4 exp, SMR 123) due to an excess of coronary deaths (18 obs, 12.4 exp, SMR 145). The cardiovascular mortality was not affected by the duration of occupational exposure or follow up period in this cohort. Among the men exposed to hydrogen sulphide and organic sulphides (4179 person-years), there was also an excess of cardiovascular deaths (37 obs, 24.7 exp, SMR 150) due to an excess of coronary deaths (25 obs, 16.7 exp, SMR 150). These excesses increased with longer follow up period. As common risk factors of coronary heart disease could not explain the findings in the sulphate mill cohort, they may be associated with exposure to hydrogen sulphide and organic sulphides.