Childhood cancer aetiology is poorly understood and is considered to originate in utero and early postnatal life. In this study, we investigated perinatal characteristics as potential risk factors by performing a population-based case-control study, including 1340 cancer cases diagnosed < 19y and born between 1989-2021 in southern Sweden, and 13400 controls matched by sex, year, and municipality of birth. Perinatal characteristics were obtained from seven national registries. Cox regression was used to examine the associations between perinatal characteristics and the risk of overall childhood cancer, leukaemia, CNS tumours, lymphoma, and other cancer types combined (OCT). Large for gestational age was associated with a higher risk of overall cancer (HR, 95%CI: 1.32, 1.02-1.69) and leukaemia (HR, 95%CI: 1.58, 1.01-2.5), while a 5-min Apgar score <7 indicated a higher risk of OCT (HR, 95%CI: 2.16, 1.12-4.15). Mechanical ventilation during neonatal care was associated with a higher risk of overall cancer (HR, 95%CI: 1.88, 1.39-2.53) and OCT (HR, 95%CI: 2.09, 1.19-3.39). The aforementioned characteristics were associated with up to a threefold increased risk among children diagnosed before six months of age compared to those diagnosed later. Additionally, maternal obesity was associated with a higher risk of CNS tumours (HR, 95%CI: 1.51, 1.04-2.21) and lymphoma (HR, 95%CI: 2.26, 1.31-3.88), and maternal underweight with a higher risk of leukaemia (HR, 95%CI: 2.43, 1.40-4.22). Planned caesarean delivery indicated an increased risk of OCT (HR, 95%CI: 1.52, 1.04-2.22). Our findings identify several perinatal characteristics associated with childhood cancer risk, highlighting the perinatal period as an important window for future etiological research.

Many women are occupationally active during pregnancy. The aim of this study was to investigate associations between exposure to chemicals during pregnancy and the risk of gestational diabetes or preeclampsia. The cohort included singleton births in Sweden between 1994 and 2014. The cohort was limited to low-educated mothers to reduce potential confounding from unidentified life-style associated factors. Information on occupation (full-time employed) at beginning of pregnancy, demographic data, education, personal risk factors and medical diagnoses were obtained from national records. Occupational exposure to 20 chemicals/particles was assessed by a time-specific job exposure matrix (SweJEM). Relative risks (RR) were adjusted for birth year of the child and mother's age, parity, country of birth, smoking, BMI, and occupational exposure to physical strain, low decision authority, noise, and whole-body vibrations. There were 307,985 births in the cohort. The risk of preeclampsia was elevated after exposure to diesel engine exhaust (RR 1.19; 95 % CI 1.03-1.37), gasoline engine exhaust (RR 1.26; 1.05-1.52) or to carbon monoxide (RR 1.21; 1.03-1.42). Exposure to lead was associated with an elevated risk of gestational diabetes, (RR 2.41; 1.05-5.55), based on six cases only, though. An elevated risk of preeclampsia in association with combustion products is corroborated by studies of traffic-related urban air pollution and of smoke from wildfires. Exposure to motor exhaust during pregnancy should be minimised. Exposure to lead during pregnancy should be avoided also because of serious neurodevelopmental effects for the child.

The purpose of this case-control study was to investigate the associations between maternal serum concentrations of vitamin D early in pregnancy and the occurrence of preterm birth. The study included 269 women (cases) whose children were born preterm (< 37 gestational weeks [gw]) and 332 women (controls) whose children were born term (≥ 37 gw). Among the cases, 59 were extreme preterm (< 28 gw), 74 severe preterm (28‒32 gw), and 136 late preterm (33‒36 gw). All women gave birth in Scania, the most Southern County of Sweden. Concentrations of 25-hydroxyvitamin D3 (vitamin D) in maternal serum collected early in pregnancy were analyzed using liquid chromatography-tandem-mass-spectrometry (LC/MS/MS). The serum concentrations of vitamin D were trichotomized based on the distributions among the controls (≤ 44.9; 45.0‒68.8; and ≥ 68.9 nmol/L) as well as dichotomized at a predefined cut-off (< 50 and ≥ 50 nmol/L). Logistic regression was used to estimate the associations between vitamin D and preterm births, partly when all cases were included in the analyses, and partly when the three different case groups were included separately. The category with the highest vitamin D concentration was used as a reference in the regression analyzes. The analyses were performed without as well as with adjustments for potential confounders. When the category with the lowest vitamin D concentrations were compared with the reference category in the analyses where the vitamin D concentrations were trichotomized, no statistically significant associations were observed. However, among the extreme preterm an adjusted odds ratio of 1.93 (95

PURPOSE:Given the paucity of data regarding workplace risk of COVID-19, particularly from countries with limited lockdowns, we aimed to quantify the occupational risks of COVID-19-related hospital admission among workers in Sweden. METHODS:We identified 607,179 employed individuals, 20-69 years of age, in Skåne, Sweden. From December 31st, 2019-December 31st 2021, 2,633 incident COVID-19-related admissions were identified. Using a job exposure matrix for risk of becoming infected with the SARS-CoV-2 virus in an occupational setting we delineated occupations with low work-related risk. Based on these reference occupations, incidence rate ratios (IRR) and 95% confidence intervals (CI) were computed by Poisson regression for four-digit occupations defined by the International Standard Classification of Occupations job codes (ISCO-08). RESULTS:After adjusting for various sociodemographic characteristics, risk compared to reference occupations was elevated among healthcare occupations as a group (IRR 1.31; 95% CI: 1.13-1.51), with nurses, healthcare assistants, and nursing aids having the highest IRRs (ranging from 1.28-1.54). In the educational sector, no apparent elevated overall risk was observed (IRR 1.03; 95% CI: 0.86-1.23). For the transportation sector, an overall excess risk was observed (IRR 1.34; 95% CI: 1.10-1.65), with bus and tram drivers having the highest risks. IRRs < 1 were observed among electricians, some builders, and software developers. CONCLUSION:Excess risk of COVID-19-related hospital admission was observed in many patient-facing occupations across the healthcare sector and in multiple occupations within the transportation sector. However, despite limited lockdowns and legislation, no apparent increased risks were observed in the educational or retail sales sectors.

The European Commission asked EFSA to update its 2009 risk assessment on arsenic in food carrying out a hazard assessment of inorganic arsenic (iAs) and using the revised exposure assessment issued by EFSA in 2021. Epidemiological studies show that the chronic intake of iAs via diet and/or drinking water is associated with increased risk of several adverse outcomes including cancers of the skin, bladder and lung. The CONTAM Panel used the benchmark dose lower confidence limit based on a benchmark response (BMR) of 5% (relative increase of the background incidence after adjustment for confounders, BMDL05) of 0.06 μg iAs/kg bw per day obtained from a study on skin cancer as a Reference Point (RP). Inorganic As is a genotoxic carcinogen with additional epigenetic effects and the CONTAM Panel applied a margin of exposure (MOE) approach for the risk characterisation. In adults, the MOEs are low (range between 2 and 0.4 for mean consumers and between 0.9 and 0.2 at the 95th percentile exposure, respectively) and as such raise a health concern despite the uncertainties.

Background Pandemics are linked with declining birth rates, but little is known about how the COVID-19 pandemic has influenced childbearing decisions. We aimed to investigate the associations between the COVID-19 pandemic and reproductive decisions, specifically to identify potential changes in the frequency of deliveries and induced abortions in Skåne, Sweden. Methods Using the Skåne Healthcare Register, we identified women aged 15–45 years who had at least one pregnancy-related care visit registered between 1 January 2013 and 11 November 11 2021. Deliveries and induced abortions were identified, and changes in weekly delivery and abortion counts were assessed using an interrupted time series design. Relative risks (RRs) and 95% confidence intervals (CIs) were estimated from a Poisson regression model. Results During the study period we identified 129 131 deliveries and 38 591 abortions. Compared with the counterfactual (exposed interval assuming COVID-19 had not occurred), pandemic exposure was associated with fewer deliveries (RR 0.93; 95% CI 0.89 to 0.98). For abortions, pandemic exposure appeared to be associated with fewer abortions (RR 0.95; 95% CI 0.90 to 1.00); however, age-related differences were found. Among women aged 25 years and over, pandemic exposure was more strongly associated with fewer abortions. Contrastingly, among women aged under 25 years, abortions appeared to increase. Conclusions The COVID-19 pandemic seemed to have contributed to a decline in births in Southern Sweden. During the same period, abortions declined in women in the older age range, but contrastingly increased among younger women.

Objective To investigate whether maternal paracetamol use in early pregnancy is associated with cerebral palsy (CP) in offspring. Study design We conducted a registry and biobank-based case-control study with mother-child pairs. We identified CP cases (n = 322) born between 1995 and 2014 from a nationwide CP-registry. Randomly selected controls (n = 343) and extra preterm controls (n = 258) were obtained from a birth registry. For each mother, a single serum sample from early pregnancy (gestation weeks 10-14) was retrieved from a biobank and analyzed for serum concentrations of paracetamol, categorized into unexposed (<1 ng/ml), mildly exposed (1-100 ng/ml), and highly exposed (>100 ng/ml), and in quartiles. Analyses were performed using logistic regression and adjusted for potential confounders. Separate analyses were conducted including only those children born preterm and only those born term. Results Of the 923 participants, 36.8% were unexposed, 53.2% mildly exposed, and 10% highly exposed to paracetamol. Overall, prenatal exposure to paracetamol was not associated with CP. Sensitivity and subgroup analyses showed no clear associations between paracetamol and CP across strata of term/preterm birth as well as subtypes of CP. Conclusions The present study does not support an association between intrauterine exposure to paracetamol in early pregnancy and the risk of CP. However, it is important to stress that the exposure estimate is based on a single serum sample.

Annex F presents a summary of the BMD analyses (BMRs of 1, 5, 10, and 50% as relative increase of the background incidence after adjustment for confounders). It includes important modelling outcomes such as BMD, BMDL, and BMDU values, and compares these results to the criteria specified in the EFSA BMD guidance (EFSA Scientific Committee, 2022). Study-specific details and BMD input parameters are also provided.

BACKGROUND:Foreign-born workers in high-income countries experience higher rates of COVID-19 but the causes are only partially known.AIMS:To examine if the occupational risk of COVID-19 in foreign-born workers deviates from the risk in native-born employees in Denmark.METHODS:Within a registry-based cohort of all residents employed in Denmark (n = 2 451 542), we identified four-digit DISCO-08 occupations associated with an increased incidence of COVID-19-related hospital admission during 2020-21 (at-risk occupations). The sex-specific prevalence of at-risk employment in foreign born was compared with the prevalence in native born. Moreover, we examined if the country of birth modified the risk of a positive SARS-CoV-2 polymerase chain reaction (PCR) test and COVID-19-related hospital admission in at-risk occupations.RESULTS:Workers born in low-income countries and male workers from Eastern Europe more often worked in at-risk occupations (relative risks between 1.16 [95% confidence interval {CI} 1.14-1.17] and 1.87 [95% CI 1.82-1.90]). Being foreign-born modified the adjusted risk of PCR test positivity (test for interaction P < 0.0001), primarily because of higher risk in at-risk occupations among men born in Eastern European countries (incidence rate ratio [IRR] 2.39 [95% CI 2.09-2.72] versus IRR 1.19 [95% CI 1.14-1.23] in native-born men). For COVID-19-related hospital admission, no overall interaction was seen, and in women, country of birth did not consistently modify the occupational risk.CONCLUSIONS:Workplace viral transmission may contribute to an excess risk of COVID-19 in male workers born in Eastern Europe, but most foreign-born employees in at-risk occupations seem not to be at higher occupational risk than native born.

Small for gestational age (SGA) is considered an adverse birth outcome. Per- and polyfluoralkyl substances (PFAS) have become increasingly investigated as contributing environmental factors, thus far with inconclusive results. The current study aimed to investigate the hypothesized association between increased maternal PFAS levels in early pregnancy and an increased risk for SGA birth. This population-based study used data from a sample of children born in Scania, Southern Sweden, between 1995 and 2009. Two groups were compared: cases born with SGA (n = 298) and non-SGA controls (n = 580). The cases consisted of two subgroups: one included women whose children’s growth in late pregnancy was in the lowest quartile, and another included women from the remaining growth quartiles. Corresponding maternal serum samples were collected from a biobank and analyzed for concentrations of four types of PFAS: perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS), and perfluorooctane sulfonic acid (PFOS) using liquid chromatography–tandem mass spectrometry (LC/MS/MS). The results were combined with information from birth registers and analyzed using Mann–Whitney U-tests and logistic regression—unadjusted as well as adjusted for potential confounders. In conclusion, elevated maternal concentrations of PFAS were not associated with an increased risk of SGA birth. However, significant ORs were observed in a subgroup analysis restricted to women of Nordic origin (unadjusted OR 3.2 and adjusted OR 2.4) for PFHxS.

In this study, the long-term mortality effects associated with exposure to PM10 (particles with an aerodynamic diameter smaller than or equal to 10 µm), PM2.5 (particles with an aerodynamic diameter smaller than or equal to 2.5 µm), BC (black carbon), and NOx (nitrogen oxides) were analyzed in a cohort in southern Sweden during the period from 1991 to 2016. Participants (those residing in Malmö, Sweden, born between 1923 and 1950) were randomly recruited from 1991 to 1996. At enrollment, 30,438 participants underwent a health screening, which consisted of questionnaires about lifestyle and diet, a clinical examination, and blood sampling. Mortality data were retrieved from the Swedish National Cause of Death Register. The modeled concentrations of PM10, PM2.5, BC, and NOx at the cohort participants’ home addresses were used to assess air pollution exposure. Cox proportional hazard models were used to estimate the associations between long-term exposure to PM10, PM2.5, BC, and NOx and the time until death among the participants during the period from 1991 to 2016. The hazard ratios (HRs) associated with an interquartile range (IQR) increase in each air pollutant were calculated based on the exposure lag windows of the same year (lag0), 1–5 years (lag1–5), and 6–10 years (lag6–10). Three models were used with varying adjustments for possible confounders including both single-pollutant estimates and two-pollutant estimates. With adjustments for all covariates, the HRs for PM10, PM2.5, BC, and NOx in the single-pollutant models at lag1–5 were 1.06 (95% CI: 1.02–1.11), 1.01 (95% CI: 0.95–1.08), 1.07 (95% CI: 1.04–1.11), and 1.11 (95% CI: 1.07–1.16) per IQR increase, respectively. The HRs, in most cases, decreased with the inclusion of a larger number of covariates in the models. The most robust associations were shown for NOx, with statistically significant positive HRs in all the models. An overall conclusion is that road traffic-related pollutants had a significant association with mortality in the cohort.

BACKGROUND:Leakage of fire-fighting foam from an airfield caused contamination of the drinking water supplied to a third of the population in Ronneby, resulting in very high serum levels of predominantly perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonate (PFHxS). The results of studies investigating the association between exposure to perfluorinated alkyl substances (PFAS) and pregnancy complications are inconsistent, and studies at high exposures of PFOS and PFHxS are lacking. OBJECTIVES:To investigate the association between exposure to high levels of PFAS and gestational hypertension and preeclampsia, and gestational diabetes mellitus. METHODS:We retrieved data on 27 292 childbirths between 1995 and 2013 from the National Medical Birth Register for women that had a residential address in Blekinge county for at least one year before delivery. Residential history was used as a proxy for exposure by categorizing women into high-, intermediate-, or background exposed based on their residential address during the five-year period before childbirth. Data on confounders were retrieved from administrative registers. The outcomes were defined based on International Classification of Diseases codes. We used logistic regression to estimate odds ratios (OR) for gestational hypertension and preeclampsia, and gestational diabetes mellitus. We also investigated effect modification by fetal sex. RESULTS:We found no evidence of increased risk of gestational hypertension and preeclampsia (OR 0.80; CI 0.63-1.03), nor gestational diabetes (OR 1.03; CI 0.67-1.58) after high PFAS exposure. There was no effect modification by fetal sex. DISCUSSION:This was the first study to investigate the association between high exposure to PFOS and PFHxS and pregnancy complications. The results from this study add important knowledge to public health management as new hotspots with high levels of PFAS are continuously discovered.

In this study, long-term mortality effects associated with exposure to PM10, PM2.5, BC (black carbon), and NOx were analyzed in a cohort in southern Sweden during the period from 1991‒2016. Participants (those residing in Malmö, Sweden, born between 1923‒1950) were randomly recruited from 1991‒1996. At enrollment, 30,438 participants underwent a health screening, which consisted of questionnaires about lifestyle and diet, a clinical examination, and blood sampling. Mortality data were retrieved from the Swedish national cause of death register. The modeled concentrations of PM10 (particles with an aerodynamic diameter smaller than or equal to 10 µm), PM2.5 (particles with an aerodynamic diameter smaller than or equal to 2.5 µm), BC (black carbon), and NOx (nitrogen oxides) at the cohort participants' home addresses were used to assess air pollution exposure. Cox proportional hazard models were used to estimate the associations between long-term exposure to PM10, PM2.5, BC, and NOx and the time until death among the participants during the period from 1991‒2016. The hazard ratios (HRs) associated with an interquartile range (IQR) increase in each air pollutant were calculated based on the exposure lag windows of the same year (lag0), 1‒5 years (lag1‒5), and 6‒10 years (lag6‒10). Three models were used with varying adjustments for possible confounders including both single-pollutant estimates and two-pollutant estimates. With adjustments for all covariates, the HRs for PM10, PM2.5, BC, and NOx in the single-pollutant models at lag1‒5 were 1.06 (95% CI: 1.02‒1.11), 1.01 (95% CI: 0.95‒1.08), 1.07 (95% CI: 1.04‒1.11), and 1.11 (95% CI: 1.07‒1.16) per IQR increase, respectively. The HRs were in most cases decreased by the inclusion of a larger number of covariates in the models. The most robust associations were shown for NOx, with statistically significant positive HRs in all models. An overall conclusion is that road traffic-related pollutants had a significant association with mortality in the cohort.

Background: Most cerebral palsy (CP) cases have an unexplained etiology, but a role for environmental exposures has been suggested. One purported environmental risk factor is exposure to endocrine-disrupting pollutants specifically per- and polyfluoroalkyl substances (PFAS).Objectives: We investigated the association between prenatal PFAS exposures and CP in Swedish children. Methods: In this case-control study, 322 CP cases, 343 population controls, and 258 preterm controls were identified from a birth registry in combination with a CP follow-up program from 1995 to 2014 and linked to a biobank which contains serum samples from week 10-14 of pregnancy. Maternal serum concentrations of four PFAS compounds: perfluorohexane sulfonate (PFHxS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorooctane sulfonate (PFOS) were analyzed using liquid chromatography-tandem-massspectrometry. We estimated odds ratios (ORs) and 95 % confidence intervals (CIs) for CP and each PFAS in quartiles and as continuous variables controlling for various sociodemographic and lifestyle factors.Results: In crude and adjusted analyses, we did not find consistent evidence of associations between serum PFHxS, PFOA, PFNA, PFOS and concentrations in early pregnancy and CP, except in preterm infants. The ORs comparing the highest PFAS quartiles to the lowest were 1.05 (95 % CI: 0.63-1.76), 0.96 (95 % CI: 0.55-1.68), 0.71 (95 % CI: 0.41-1.25), and 1.17 (95 % CI: 0.61-2.26), for PFHxS, PFOA, PFNA, and PFOS, respectively. Some positive associations were observed for preterm infants, but the results were imprecise. Similar patterns were observed in analyses treating PFAS as continuous variables. Conclusions: In this study, we found little evidence that early pregnancy prenatal exposure to PFHxS, PFOA, PFNA, or PFOS increases the risk of CP. However, some positive associations were observed for preterm cases and warrant further investigation.

BACKGROUND:Preeclampsia is considered a major cause of maternal and fetal morbidity and mortality. The aim of the present case-control study in Sweden was to assess the hypothesized association between low serum vitamin D concentrations in early pregnancy and the risk of developing preeclampsia since vitamin D may play a role in early placental development. METHODS:The study included 296 women diagnosed with preeclampsia (cases) and 580 healthy pregnant women (controls). Serum samples were obtained from a biobank of samples collected in early pregnancy including almost all pregnancies in Southern Sweden. Concentrations of 25-hydroxyvitamin D3 (vitamin D) were analyzed using liquid chromatography-tandem-mass-spectrometry (LC/MS/MS). The cases were divided into two categories: i) infants were born before gestational week 34 (early onset) and/or born small-for-gestational age (SGA)(n = 51), ii) and others defined as late onset (n = 245). Vitamin D concentrations were analyzed both as a continuous and a categorized variable. RESULTS:When all preeclampsia cases were included in the analyses no consistent patterns were observed. However, the median serum concentrations of vitamin D were significantly lower among the cases who were early onset and/or were born SGA (median 39.2 nmol/L, range 1.2-93.6) as compared to the controls (49.0 nmol/L, 0.1-219; p = 0.01). In addition, high concentrations were statistically significantly associated with a decreased risk of preeclampsia (>66.9 vs ≤30.1 nmol/L; crude OR 0.39, 95% CI 0.16-0.96). When potential confounders were included in the models the associations were even more pronounced. CONCLUSIONS:Our results support the hypothesis that vitamin D deficiency is a risk factor for preeclampsia, but only in preeclampsia cases who were early-onset and/or were born SGA. Preeclampsia is not a homogenous condition and more studies are needed before vitamin D supplementation during pregnancy can be recommended.

Objective This study aimed to quantify the risk of COVID-19-related hospital admission in spouses living with partners in at-risk occupations in Denmark during 2020-21.Methods Within a registry-based cohort of all Danish employees (N=2 451 542), we identified cohabiting couples, in which at least one member (spouse) held a job that according to a job exposure matrix entailed low risk of occupational exposure to SARS-CoV-2 (N=192 807 employees, 316 COVID-19 hospital admissions). Risk of COVID-19-related hospital admission in such spouses was assessed according to whether their partners were in jobs with low, intermediate or high risk for infection. Overall and sex-specific incidence rate ratios (IRR) of COVID-19-related hospital admission were computed by Poisson regression with adjustment for relevant covariates.Results The risk of COVID-19-related hospital admission was increased among spouses with partners in highrisk occupations [adjusted IRR (IRRadj)1.59, 95% confidence interval (CI) 1.1-2.2], but not intermediate-risk occupations (IRRadj 0.97 95% 0.8-1.3). IRR for having a partner in a high-risk job was elevated during the first three pandemic waves but not in the fourth (IRRadj 0.48 95% CI 0.2-1.5). Sex did not modify the risk of hospital admission.Conclusions SARS-CoV-2 transmission at the workplace may pose an increased risk of severe COVID-19 among spouses in low-risk jobs living with partners in high-risk jobs, which emphasizes the need for preventive measures at the workplace in future outbreaks of epidemic contagious disease. When available, effective vaccines seem essential.

Objective To map the risk of work-related SARS-CoV-2 across occupations and pandemic waves and investigate its impact on morbidity and partner-risk. Methods The cohort includes 2,4 million employees aged 20–69 with follow-up from 2020 through 2021. During this period, 261,203 employees had a positive SARS-CoV-2 test and 4416 were admitted to hospital with Covid-19 (HA). At-risk occupations defined at the 4-digit DISCO-08 level were identified using a reference population of mainly office-workers defined a priory by a job-exposure matrix (JEM). Incidence rate ratios (IRR) and effect modification by pandemic wave were computed by Poisson regression. We adjusted for demographic, social and health characteristics including household size, completed Covid-19 vaccination and occupation-specific frequency of testing. Results In addition to eight specific occupations in the healthcare sector, we found increased risk of Covid-19 related HA in bus drivers, kindergarten teachers, domestic helpers, and operators in food production (IRR from 1.5–3) and modestly increased risk of SARS-CoV-2 infection in numerous occupations outside the healthcare sector including police and security guards, supermarket attendants, receptionists, cooks, and waiters. After the first year of the pandemic, the risk fell to background levels among healthcare workers but not in other occupations. The risk of Covid-19 related HA was increased in spouses with partners in high-risk occupations (IRR 1.54, 95% CI 1.1–2.2). Employees born in low-income countries and male employees from Eastern Europe more often worked in at-risk occupations. Being foreign-born modified the risk of PCR test positivity, primarily because of higher risk among men born in Eastern Europe working in at-risk occupations (IRR 2.39, 95% CI 2.09–2.72 versus IRR 1.19 (95% CI 1.14–1.23) in native-born men). Conclusion SARS-Cov2 transmission at the workplace was common during the Covid-pandemic in spite of temporary lock-downs which emphasizes the need for improved safety measures during future epidemics.

ABSTRACTObjectivesMost earlier studies on occupational risk of Covid-19 covering the entire workforce are based on relatively rare outcomes such as hospital admission and mortality. This study examines the incidence of SARS-CoV-2 infection by occupational group based upon real-time polymerase chain reaction tests (RT-PCR).MethodsThe cohort includes 2.4 million Danish employees, 20-69 years of age. All data were retrieved from public registries. The sex-specific incidence rate ratios (IRR) of first-occurring positive RT-PCR test from week 8 of 2020 through week 50 of 2021 were computed by Poisson regression for each 4-digit DISCO-08 job code with more than 100 employees (337 in men; 297 in women). Occupational groups with low risk of workplace infection according to a job exposure matrix constituted the reference group. Risk estimates were adjusted by demographic, social and health characteristics including household size, completed Covid-19 vaccination, pandemic wave and occupation-specific frequency of testing.ResultsIRR’s of SARS-CoV-2 infection were elevated in 34 occupations comprising 12 % of male employees and 45 occupations comprising 41 % of female employees. All IRR estimates were below 2.0. Decreased IRRs were observed in 85 occupations in men but none in women.DiscussionWe observed a modestly increased risk of SARS-CoV-2 infection among employees in numerous occupations indicating a large potential for preventive actions, especially in the female workforce. Cautious interpretation of observed risk in specific occupations is needed because of methodological issues inherent in analyses of RT-PCR-test results and because of multiple statistical tests.WHAT IS ALREADY KNOW ABOUT THIS TOPIC?Epidemiological studies suggest that the workplace contribute to the Covid-19 pandemicResults are mostly based upon studies of less frequent outcomes as Covid-19 morbidity or mortality which limits inference about risk in specific occupationsWHAT THIS STUDY ADDSThe risk of Covid-19 infection was increased in 34 of 337 occupations in men and in 45 of 297 occupations in womenSome 12% of the Danish male workforce and 41% of the female workforce are at increased risk of Covid-19 infectionHOW THIS RESEARCH MIGHT AFFECT RESEARCH, PRACTICE OR POLICY?Preventive actions targeting the workplace may contribute substantially to alleviate disease occurrence in the ongoing Covid-19 and similar future pandemics.

Objective Mounting evidence indicates increased risk of COVID-19 among healthcare personnel, but the evidence on risks in other occupations is limited. In this study, we quantify the occupational risk of COVID-19-related hospital admission in Denmark during 2020–2021. Methods The source population included 2.4 million employees age 20–69 years. All information was retrieved from public registers. The risk of COVID-19 related hospital admission was examined in 155 occupations with at least 2000 employees (at-risk, N=1 620 231) referenced to a group of mainly office workers defined by a COVID-19 job exposure matrix (N=369 341). Incidence rate ratios (IRR) were computed by Poisson regression. Results During 186 million person-weeks of follow-up, we observed 2944 COVID-19 related hospital admissions in at-risk occupations and 559 in referents. Adjusted risk of such admission was elevated in several occupations within healthcare (including health care assistants, nurses, medical practitioners and laboratory technicians but not physiotherapists or midwives), social care (daycare assistants for children aged 4–7, and nursing aides in institutions and private homes, but not family daycare workers) and transportation (bus drivers, but not lorry drivers). Most IRR in these at-risk occupations were in the range of 1.5–3. Employees in education, retail sales and various service occupations seemed not to be at risk. Conclusion Employees in several occupations within and outside healthcare are at substantially increased risk of COVID-19. There is a need to revisit safety measures and precautions to mitigate viral transmission in the workplace during the current and forthcoming pandemics.