Documents Nordby, Karl-Christian 5 results

"Background
The association between occupational titles and lung function has mostly been examined through cross-sectional studies. Preventive measures are expected to mitigate adverse effects; hence, updated estimates are necessary.
Aims
To study change in lung function measured by spirometry across occupations.
Methods
This population-based prospective cohort study comprised 5618 working adult participants of the Trøndelag Health Study (HUNT3, 2005–07), Norway. Among these, 3800 individuals (43% men, mean age 42 years, range 20–55) also attended HUNT4 (2017–19). We analysed longitudinal decline in forced expiratory volume in 1 second (FEV1) z-score during the 11-year follow-up by occupation (white-collar workers as reference category), in mixed models, adjusting for age, sex and smoking. We assessed the prevalence of self-reported respiratory symptoms and disease in the working population in HUNT4 (n = 32 124) and HUNT3 (n = 32 070).
Results
Compared with white-collar workers, agricultural workers and ‘drivers and mobile plant operators', had larger declines in FEV1z-score during follow-up. In sex-stratified analyses, men defined as agricultural workers and ‘drivers and mobile plant operators' had larger declines than white-collar workers. Among women, who were underrepresented in many blue-collar jobs, workers classified as ‘machine operators and assemblers' experienced greater declines. In the working population in HUNT4, the prevalence of respiratory symptoms in connection with work was 8%, and lower among white-collar workers (6%) than blue-collar workers (14%).
Conclusions
Although certain workers in Norway remain at risk for occupational lung function decline, there were modest differences between occupations. The findings encourage continuous efforts to implement preventive measures in high-risk jobs."

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"Background
Pesticides are commonly used in agriculture, and previous studies endorsed the need to further investigate the possible association between their use and risk of lymphoid malignancies in agricultural workers.
Methods
We investigated the relationship of ever use of 14 selected pesticide chemical groups and 33 individual active chemical ingredients with non-Hodgkin lymphoid malignancies (NHL) overall or major subtypes, in a pooled analysis of three large agricultural worker cohorts. Pesticide use was derived from self-reported history of crops cultivated combined with crop-exposure matrices (France and Norway) or self-reported lifetime use of active ingredients (USA). Cox regression models were used to estimate cohort-specific hazard ratios (HRs) and 95% confidence intervals (CIs), which were combined using random effects meta-analysis to calculate meta-HRs.
Results
During follow-up, 2430 NHL cases were diagnosed in 316 270 farmers accruing 3 574 815 person-years under risk. Most meta-HRs suggested no association. Moderately elevated meta-HRs were seen for: NHL and ever use of terbufos (meta-HR = 1.18, 95% CI: 1.00–1.39); chronic lymphocytic leukaemia/small lymphocytic lymphoma and deltamethrin (1.48, 1.06–2.07); and diffuse large B-cell lymphoma and glyphosate (1.36, 1.00–1.85); as well as inverse associations of NHL with the broader groups of organochlorine insecticides (0.86, 0.74–0.99) and phenoxy herbicides (0.81, 0.67–0.98), but not with active ingredients within these groups, after adjusting for exposure to other pesticides.
Conclusions
Associations of pesticides with NHL appear to be subtype- and chemical-specific. Non-differential exposure misclassification was an important limitation, showing the need for refinement of exposure estimates and exposure–response analyses."

"Background
Testing of vibration perception threshold (VPT) at the fingertips as a quantitative measure of tactile sensitivity is a commonly used tool in diagnosing hand–arm vibration syndrome. There is limited research on dose–response relationships between hand–arm vibration (HAV) exposure and VPT on an individual level.
Aims
Assess possible dose–response relationships on an individual level between HAV exposure and VPT at the fingertips.
Methods
We assessed average daily vibration exposure (m/s2A8) and cumulative lifetime HAV exposure for 104 participants from different departments in a road maintenance company based on vibration measurements and questionnaires. VPT was measured based on the technical method described in ISO 13091-1:2005 using octave frequencies 8–500 Hz. We investigated associations using linear regression models with significance level p≤0.05.
Results
The participants were either exposed to rock drills (n=33), impact wrenches (n=52) or none of these tools (n=19). Exposure to rock drills and impact wrenches was associated with elevated VPT for all seven test frequencies in the second and fifth fingers of both hands. A dose–response with the daily exposure measure m/s2(A8) was found based on 1.2 m/s2(A8) for impact wrenches, and 5.4 m/s2(A8) for rock drills. A stronger association was found with the cumulative exposure for rock drills compared with impact wrenches, and for the second finger compared with the fifth finger.
Conclusions
HAV exposure was associated with elevated VPT, also at exposure levels below the common exposure action value of 2.5 m/s2(A8). Lowering the HAV exposure can contribute to prevent increasing VPTs in these workers."

"Objectives
Increased risks of bladder cancer and mesothelioma were the strongest evidence for the recent reclassification of firefighting as carcinogenic (Group 1) by the International Agency for Research on Cancer. Our study aim was to develop indicators for specific firefighting exposures and examine associations with urinary tract cancer (UTC), including bladder cancer.
Methods
We developed indicators for exposure from employment at a fire department or in firefighting jobs, to fire and smoke, and to diesel exhaust for men in the Norwegian Fire Departments Cohort (n=4250). Incident UTC cases were obtained from the Cancer Registry of Norway (1960–2021). Poisson regression was used to estimate incidence rate ratios (IRR) with cumulative exposures grouped into tertiles (reference: lowest exposed tertile) with 0-year, 10-year and 15-year lagging of exposures.
Results
During 125 090 person-years of follow-up, there were 76 cases of UTC. IRRs were mostly non-significantly increased in the middle tertile and at or below 1 in the highest tertile for total duration of employment, number of fires attended and fire exposure score with and without lags. In the middle tertile for diesel exhaust exposure, UTC risk was elevated over twofold with 10-year (IRR 2.27, 95% CI 1.22 to 4.20) and 15- year (2.21, 1.18 to 4.16) lags, and near 1 in the highest tertile. Findings for bladder cancer were similar to those for UTC.
Conclusions
Dose-response associations between the exposure indicators and UTC were not observed. Future studies using the indicators with more cases are needed."

"We investigated the level of protection of reproductive and developmental toxicity offered through occupational exposure limits (OELs) and Derived No-Effect Levels for workers' inhalation exposure (wDNELs). We compared coverage of substances that have a harmonised classification as reproductive toxicant 1 A or 1B (Repr.1 A/B), numerical values and scientific basis of 12 lists of OELs and wDNELs from REACH Registrants' and the Committee for Risk Assessment. Across the 14 sources of OELs and wDNELs, 53 % of the Repr1A/B-substances had at least one exposure limit (counting groups of metals as one entry). Registrants' wDNELs covered the largest share, 40 %. The numerical values could be highly variable for the same substance across the lists. How often reproductive toxicity is identified as the critical effect varies between the examined lists, both due to different assessments of the same substance and different substance coverage. Reviewing the margin of safety to reproductive toxicity cited in the documents, we found that 15 % of safety margins were lower to reproductive toxicity than the critical effect. To conclude, neither the REACH nor work environment legislation supply wDNELs or OELs for a substantial share of known reproductive toxicants. EU OELs cover among the fewest substances in the range, and in many cases national OELs or wDNELs are set at more conservative levels."