Occurrence of respiratory symptoms and lung function deficits among fruit and vegetable market workers

OBJECTIVE

The objective of this study was to investigate the potential effects of occupational exposures among fruit and vegetable market workers on the occurrence of respiratory symptoms and on the level of lung function parameters.

METHODS

We conducted a cross-sectional study of 140 men working as fruit and vegetable market workers (response rate 100%) and a reference group of 77 male office workers as the reference group (response rate 55%) from Shiraz, Iran. The outcomes of interest included occurrence of respiratory symptoms assessed by a standard respiratory questionnaire and lung function assessed by spirometry.

RESULTS

In Poisson regression analyses, the exposed group showed increased prevalence ratio (PR) of wheezing (adjusted PR 5.32, 95% CI 1.40 to 20.26), after controlling for confounding. Cough (PR 3.30, 95% CI 1.16 to 9.40) and wheezing (PR 9.40, 95% CI 2.28 to 38.64) showed increased PRs among vegetable distributors. Forced expiratory volume in 1 s (FEV₁) and FEV₁/forced vital capacity were significantly decreased among exposed workers after controlling for confounders. The absolute value of FEV₁ level was reduced significantly among fruit and vegetable carters (-0.99, 95% CI -1.68 to -0.32) and vegetable (-0.51, 95% CI -0.93 to -0.10) and fruit (-0.51, 95% CI -0.86 to -0.15) distributors in comparison with the reference group in the adjusted full model.

CONCLUSIONS

This study provides evidence that fruit and vegetable market workers are at an increased risk of respiratory symptoms and reduced lung function. Workplace conditions and safety training clearly need improvement, and there is a likely role for proper use of personal protective equipment.

Occupational exposure to soft paper dust and mortality

OBJECTIVES

Occupational exposure to soft paper dust is associated with impaired lung function. Whether there is an increased risk for asthma or chronic obstructive pulmonary disease (COPD) is unclear.

METHODS

We studied 7870 workers from three Swedish soft paper mills, and defined high-exposed workers, as having been exposed to soft paper dust exceeding 5 mg/m³ for at least 5 years. The remaining workers were classified as 'low exposed'. Person-years at risk were calculated and stratified according to gender, age and calendar-year. The follow-up time was from 1960 to 2013. The expected numbers of deaths were calculated using the Swedish population as reference and standardised mortality ratios (SMRs) with 95% CIs were assessed.

RESULTS

There was an increased mortality due to obstructive lung disease (asthma and COPD), among high-exposed workers, SMR 1.89, 95% CI 1.20 to 2.83, based on 23 observed cases. High-exposed workers had an increased mortality from asthma, SMR 4.13, 95% CI 1.78 to 8.14, based on eight observed cases. The increased asthma mortality was also observed among high-exposed men, SMR 4.38, 95% CI 1.42 to 10.2, based on five observed cases. The asthma mortality among low-exposed workers, both men and women, was not increased. The COPD mortality was not clearly increased among high-exposed workers (SMR 1.52, 95% CI 0.85 to 2.50).

CONCLUSION

High occupational exposure to soft paper dust increases the mortality due to asthma, and the results suggest that soft paper dust levels in workplaces should be below 5 mg/m³.

Dietary Patterns and Prevalence of Post-bronchodilator Airway Obstruction in Dairy Farmers Exposed to Organic Dusts

Exposure to organic dusts is an independent causative factor of chronic obstructive pulmonary disease (COPD). Unhealthy dietary patterns have been associated with poor lung function in smokers. This study investigated whether dietary patterns were associated with post-bronchodilator airway obstruction, a hallmark of COPD, in dairy farmers exposed to organic dusts. All subjects were identified by screening programs and patients with airflow obstruction were matched with subjects with normal spirometry. Six groups were compared, defined by their exposures (non-smoking dairy farmers, smokers ≥ 10 pack-years with no occupational exposure, and smoking dairy farmers) and the presence or absence of post-bronchodilator airflow obstruction, resulting in 321 study subjects. The Alternative Healthy Eating Index (AHEI) score was calculated based on an adapted food frequency questionnaire. Mean total AHEI scores were similar in all groups. Comparison between smokers with post-bronchodilator airway obstruction and subjects with post-bronchodilator airway obstruction related to occupational exposure found minimal differences in dietary patterns: dairy farmers had lower scores for the ratio of white to red meat and higher scores for cereal fiber consumption. As in previous studies, smokers with post-bronchodilator airway obstruction exhibited higher lipid intakes and lower carbohydrate intakes than their counterparts with normal spirometry. No evidence of any meaningful difference in dietary patterns was found between subjects with post-bronchodilator airway obstruction detected by screening and healthy controls, either in dairy farmers or in smokers with no occupational exposure.

Occupational exposure to organic particles and combustion products during pregnancy and birth outcome in a nationwide cohort study in Sweden

Objective

To study if children of women exposed to organic particles and combustion products at work during pregnancy, have an increased risk of low birth weight, preterm birth or small for gestational age.

Methods

A nationwide cohort of all occupationally active mothers and their children from single births during 1994 to the end of 2012 (1 182 138 observations) was formed. Information on birth outcome was obtained from the medical birth register. Information on absence from work, education, occupation, age, nationality and smoking habits was obtained from national registers. A job exposure matrix (FINJEM) was used to assess the exposure.

Results

Pregnant women with low absence from work and high (>50th percentile) exposure to organic particles had an increased risk of giving birth to children with low birth weight (OR=1.19; 95% CI: 1.07 to 1.32), small for gestational age (OR=1.22; 95% CI: 1.07 to 1.38) or preterm birth (OR=1.17; 95% CI: 1.08 to 1.27). Subgroup analyses showed an increased risk of small for gestational age in association with exposure to oil mist. Exposure to oil mist and cooking fumes was associated with low birth weight. Paper and other organic dust was associated with preterm birth. Exposure to combustion products showed an increased risk of small for gestational age (OR=1.40; 95% CI: 1.15 to 1.71).

Conclusions

The results indicate that occupational exposure to organic particles or combustion products during pregnancy is associated with restriction of fetal growth and preterm birth. More studies are needed to confirm a casual association.

A nationwide follow-up study of occupational organic dust exposure and risk of chronic obstructive pulmonary disease (COPD)

Objectives

To study exposure-response relations between cumulative organic dust exposure and incident chronic obstructive pulmonary disease (COPD) among subjects employed in the Danish farming and wood industry.

Methods

We studied exposure-response relations between cumulative organic dust exposure and incident COPD (1997–2013) among individuals born during 1950–1977 in Denmark ever employed in the farming or wood industry (n=1 75 409). Industry-specific employment history (1964–2007), combined with time-dependent farming and wood industry-specific exposure matrices defined cumulative exposure. We used logistic regression analysis with discrete survival function adjusting for age, sex and calendar year. Adjustment for smoking status was explored in a subgroup of 4023 with smoking information available.

Results

Cumulative organic dust exposure was inversely associated with COPD (adjusted rate ratios (RR_adj (95% CIs) of 0.90 (0.82 to 0.99), 0.76 (0.69 to 0.84) and 0.52 (0.47 to 0.58) for intermediate-low, intermediate-high and high exposure quartiles, respectively, compared with the lowest exposure quartile). Lagging exposure 10 years was not consistently suggestive of an association between cumulative exposure and COPD; RR_adj (95% CI): 1.05 (0.94 to 1.16), 0.92 (0.83 to 1.02) and 0.63 (0.56 to 0.70). Additional stratification by duration of employment showed no clear association between organic dust exposure and COPD except for the longer exposed (15–40 years) where an inverse association was indicated. Subgroup analyses showed that smoking had no impact on exposure-response estimates.

Conclusions

Our findings show no increased risk of COPD with increasing occupational exposure to organic dust in the farming or wood industry. Potential residual confounding by smoking can, however, not be ruled out.

Chronic lung function decline in cotton textile workers: roles of historical and recent exposures to endotoxin

BACKGROUND

Long-term occupational exposure to cotton dust that contains endotoxin is associated with chronic respiratory symptoms and excessive decline in forced expiratory volume in 1 sec (FEV1), but the mechanisms of endotoxin-related chronic airflow obstruction remain unclear.

OBJECTIVE

In the current study, we examined temporal aspects of the exposure-response relationship between airborne endotoxin exposure, longitudinal change in FEV1, and respiratory symptoms in a cohort of Chinese cotton textile workers.

METHODS

This prospective cohort study followed 447 cotton textile workers from 1981 to 2006. at approximately 5-year intervals. We used a generalized estimating equations approach to model FEV1 level and respiratory symptoms as a function of past exposure (cumulative exposure up to the start of the most recent 5-year survey interval) and cumulative exposure (within the most recent interval) to endotoxins, after adjusting for other covariates. Models were stratified by active versus retired work status and by years employed before the baseline survey (< 5 and > or = 5 years).

RESULTS AND CONCLUSIONS

Past exposure to endotoxin was associated with reduced FEV1 level among retired cotton workers. Among all cotton workers, past exposure was more strongly associated with reduced FEV1 for those hired < 5 years before baseline than for those who were hired > or = 5 years after baseline. Recent endotoxin exposure was significantly associated with byssinosis, chronic bronchitis, and chronic cough.