Low birth weight in newborns to women employed in jobs with frequent exposure to organic solvents.

The effects of occupational exposure to organic solvents in pregnancy on foetal growth are still unclear. Our aim was to study whether live newborns to women employed in paid jobs with frequent exposure had a different risk of being born with low birth weight (LBW), compared to those of women in jobs without such exposure. The study population was all singleton newborns delivered in the industrial township of Moncegorsk (N = 26,415). Information about occupation and characteristics of the mothers and babies was obtained from the local population-based birth register, and registered job function was used to classify exposure. We observed an elevated risk of LBW among live, singleton newborns in the exposed group (adjusted odds ratio: 1.68 [95% CI: 1.18-2.41]), which predominantly consisted of painters. The adjusted odds of LBW in the exposed group were also higher among term-born neonates. In addition, a lower mean birth weight was observed among the exposed.

Low back pain among mineworkers in relation to driving, cold environment and ergonomics.

OBJECTIVES: We aimed to study the association between low back pain (LBP) and exposure to low temperature, wet clothes, heavy lifting and jobs that involve whole body vibration (WBV) in a population of miners. METHODS: Health and personal data were collected in a population study by a questionnaire. A total of 3530 workers from four mines participated in the study. RESULTS: 51% of the workers reported LBP within the last 12 months. The adjusted odds ratio for LBP was above unity for working with wet clothes (1.82), working in cold conditions (1.52), lifting heavy (1.54), having worked as a driver previously (1.79) and driving Toro400 (2.61) or train (1.69). CONCLUSION: Wet clothing, cold working conditions, heavy lifting, previous work as a driver and driving certain vehicles were associated with LBP, but vehicles with WBV levels above action value were not. For better prevention of LBP, improved cabin conditions and clothing should be emphasised. PRACTITIONER SUMMARY: To address risk factors for low back pain (LBP) in miners, a population study measured exposures and LBP. Cold work conditions, wet clothes and awkward postures appeared to be more strongly associated with LBP than exposure to whole body vibration from driving heavy vehicles. Prevention strategies must focus more on clothing and ergonomics.

Congenital anomalies in newborns to women employed in jobs with frequent exposure to organic solvents--a register-based prospective study.

BACKGROUND: The foetal effects of occupational exposure to organic solvents in pregnancy are still unclear. Our aim was to study the risk of non-chromosomal congenital anomalies at birth in a well-defined population of singletons born to women employed as painters and spoolers in early pregnancy, compared to women in non-hazardous occupations. METHOD: The study population for this prospective cohort study was singleton newborns delivered to working mothers in the industrial community of Moncegorsk in the period 1973-2005. Occupational information and characteristics of the women and their newborns was obtained from the local population-based birth register. RESULTS: The 597 women employed as painters, painter-plasterers or spoolers had 712 singleton births, whereof 31 (4.4%) were perinatally diagnosed with 37 malformations. Among the 10 561 newborns in the group classified as non-exposed, 397 (3.9%) had one or more malformations. The overall prevalence in the exposed group was 520/10 000 births [95% confidence limits (CL): 476, 564], and 436/10 000 births (95% CL: 396, 476) in the unexposed. Adjusted for young maternal age, smoking during pregnancy, maternal congenital malformation and year of birth, the odds ratio (OR) was 1.24 (95% CL: 0.85, 1.82); for multiple anomalies it was 1.54 (95% CL: 0.66, 3.59).The largest organ-system specific difference in prevalence between the two groups was observed for malformations of the circulatory system: 112/10 000 (95% CL: 35, 190) in the exposed group, and 42/10 000 (95% CL: 29, 54) in the unexposed, with an adjusted OR of 2.03 (95% CL: 0.85, 4.84). The adjusted ORs for malformations of the genital organs and musculoskeletal system were 2.24 (95% CI: 0.95, 5.31) and 1.12 (95% CI: (0.62, 2.02), respectively. CONCLUSION: There appeared to be a higher risk of malformations of the circulatory system and genital organs at birth among newborns to women in occupations with organic solvent exposure during early pregnancy (predominantly employed as painters). However, the findings were not statistically conclusive. Considering that these two categories of malformations are not readily diagnosed perinatally, the difference in prevalence between the exposed and unexposed may have been underestimated.

Maternal nickel exposure and congenital musculoskeletal defects.

OBJECTIVE: To investigate whether women occupationally exposed to nickel in early pregnancy are at elevated risk of delivering a newborn with a malformation or deformation of the musculoskeletal system (ICD-10: Q65-Q79). METHODS: Data about the newborn, maternal occupation and workplace were obtained using the Kola Birth Register (KBR). Each record in the KBR was assigned a categorical nickel (Ni) exposure rating according to the occupation the delivering woman had at the time of becoming pregnant. This was achieved by using as a guideline the water-soluble Ni subfraction of the inhalable aerosol fraction obtained by personal monitoring for nickel- and copper-refinery workers or/and measured urinary-Ni concentrations. The reference population was delivering women from the source population with background exposure level. In total, the study population consisted of 22,965 births. RESULTS: Three hundred and four infants (13.3/1,000 births; 95% confidence interval (CI): 11.9-14.7) were diagnosed with isolated musculoskeletal defect(s) at birth. The adjusted odds ratio for the association between the maternal exposure to Ni and this outcome was 0.96 (95% CI: 0.76-1.21) per unit increase in exposure category. CONCLUSION: The incidence of defects in the musculoskeletal system at birth was high, especially for feet deformities, but we found no effect of maternal exposure to water-soluble Ni on the risk of delivering a newborn with a defect. However, the incidence among women working in the copper refinery was higher than in the other employment groups.

Small-for-gestational-age newborns of female refinery workers exposed to nickel.

OBJECTIVES: It has not yet been established whether exposure to nickel (Ni) compounds may cause reproductive toxicity. The objective of this study was to investigate whether women employed under conditions of nickel exposure in early pregnancy were at elevated risk of delivering a newborn small-for-gestational-age (SGA). MATERIALS AND METHODS: A register-based study of a well defined population. Data on pregnancy outcome and maternal occupation were obtained from the Kola Birth Registry. Each birth record was assigned a Ni exposure rating category according to maternal occupation at the time of becoming pregnant. Nickel exposure assessment was based on determining the water-soluble Ni subfraction of respirable aerosol fraction obtained by personal monitoring, and/or on measurements of urine Ni concentration. The reference population were the delivering women with background exposure level. The study population consisted of 22 836 births (>27 weeks of gestation) and the SGA infants were defined as below the 10th percentile birth weight for gestational age in the source population. Multiple logistic regression was used to analyze the association of the outcome with the assigned exposure rating category. RESULTS: The adjusted odds ratio for Ni-exposed women for giving birth to an SGA newborn was 0.84 (95% CI: 0.75-0.93). CONCLUSIONS: We found no adverse effect of maternal occupational exposure to water-soluble Ni in the first part of pregnancy on the risk of delivering an SGA newborn without trisomy. The finding does not exclude a possibility that exposure throughout pregnancy might produce such an effect.

Pregnancy health and outcome in two cities in the Kola Peninsula, Northwestern Russia.

OBJECTIVES: The aims of the study were to compare the prevalence of selected maternal and lifestyle factors as well as the reproductive outcome of working women in two cities in Northwestern Russia (Moncegorsk and Apatity), and to assess the quality of pregnancy-outcome data obtained in an interview with registered information. STUDY DESIGN: A retrospective questionnaire study in an interview format. Women (n =1696) from selected workplaces in Apatity and Moncegorsk participated (85% of those available). Information was collected about past pregnancies, including information about the pregnancy outcome, newborn, occupation, health and life-style. RESULTS: The investigated groups had experienced 7,254 pregnancies in total, corresponding to 4.3 pregnancies on average per woman. In both groups, about one-half of the reported pregnancies were terminated, and three-quarters of the women had undergone an induced abortion. Spontaneous abortions had been experienced by 23% of the women in the Apatity group, which was higher than in the Moniegorsk group (16%). Previous spontaneous abortions appear more likely to be disclosed than induced abortions. The smoking prevalence was 37% in the Moncegorsk group and 24% in the Apatity group. Thirteen percent of all participants had been diagnosed with a pelvic inflammatory disease. CONCLUSIONS: Induced abortions were common in Northwestern Russia regardless of city of residency, and the majority of the abortions appear to have occurred after the women had their attainable or desired number of children. The proportion of pregnancies resulting in a spontaneous abortion was higher in the investigated group in Apatity than in Moncegorsk, which should be investigated further. This study also confirmed that smoking has become more widespread among women in the Kola Peninsula, as elsewhere in Russia.

Thermal comfort sustained by cold protective clothing in Arctic open-pit mining-a thermal manikin and questionnaire study.

Workers in the Arctic open-pit mines are exposed to harsh weather conditions. Employers are required to provide protective clothing for workers. This can be the outer layer, but sometimes also inner or middle layers are provided. This study aimed to determine how Arctic open-pit miners protect themselves against cold and the sufficiency, and the selection criteria of the garments. Workers' cold experiences and the clothing in four Arctic open-pit mines in Finland, Sweden, Norway and Russia were evaluated by a questionnaire (n=1,323). Basic thermal insulation (Icl) of the reported clothing was estimated (ISO 9920). The Icl of clothing from the mines were also measured by thermal manikin (standing/walking) in 0.3 and 4.0 m/s wind. The questionnaire showed that the Icl of the selected clothing was on average 1.2 and 1.5 clo in mild (-5 to +5°C) and dry cold (-20 to -10°C) conditions, respectively. The Icl of the clothing measured by thermal manikin was 1.9-2.3 clo. The results show that the Arctic open-pit miners' selected their clothing based on occupational (time outdoors), environmental (temperature, wind, moisture) and individual factors (cold sensitivity, general health). However, the selected clothing was not sufficient to prevent cooling completely at ambient temperatures below -10°C.

Musculoskeletal symptoms and exposure to whole-body vibration among open-pit mine workers in the Arctic.

OBJECTIVES: This cross-sectional questionnaire study was carried out at 4 open-pit mines in Finland, Norway, Russia and Sweden as part of the MineHealth project. The aim has been to compare the prevalence of musculoskeletal symptoms between drivers of mining vehicles and non-drivers. MATERIAL AND METHODS: The mine workers were asked whether they had suffered from any musculoskeletal symptoms during the previous 12 months in specified body regions, and to grade the severity of these symptoms during the past month. They were also asked about their daily driving of mining vehicles. RESULTS: The questionnaire was completed by 1323 workers (757 vehicle drivers) and the reported prevalence and severity of symptoms were highest for the lower back, followed by pain in the neck, shoulder and upper back. Drivers in the Nordic mines reported fewer symptoms than non-drivers, while for Russian mine workers the results were the opposite of that. The daily driving of mining vehicles had no significant association with the risk of symptoms. Female drivers indicated a higher prevalence of symptoms as compared to male drivers. CONCLUSIONS: The study provided only weak support for the hypothesis that drivers of vehicles reported a higher prevalence of musculoskeletal symptoms than non-vehicle drivers. There were marked differences in the prevalence of symptoms among workers in various enterprises, even though the nature of the job tasks was similar. Int J Occup Med Environ Health 2017;30(4):553-564.

Genital malformations in newborns of female nickel-refinery workers.

OBJECTIVES: This study investigated whether pregnant women employed in nickel-exposed work areas are at elevated risk of delivering a newborn with a genital malformation. METHODS: In this register-based cohort study, data about pregnancy outcome and occupation were obtained using the Kola Birth Registry. Each record in the Registry was assigned a categorical nickel exposure rating according to the occupation the delivering woman had at the time of becoming pregnant, using, as guidelines, the water-soluble nickel subfraction of the inhalable aerosol fraction obtained by personal monitoring for nickel-refinery workers or the measured urinary nickel concentrations. The reference population comprised delivering women from Moncegorsk with a background exposure level. The association of the outcome with the assigned exposure ratings was analyzed in a logistic regression model, adjusted for parity, maternal malformation, exposure to solvents, and infection in early pregnancy. RESULTS: The odds ratio for nickel-exposed women delivering a newborn with a genital malformation was 0.81 [95% confidence interval (95% CI) 0.52-1.26], and that for an undescended testicle was 0.76 (95% CI 0.40-1.47). CONCLUSIONS: In this study no negative effect of maternal exposure to water-soluble nickel was found on the risk of delivering a newborn with malformations of the genital organs. The results should be interpreted with caution since there were few cases in the higher exposure groups. The findings do not exclude the possibility of an effect on the risk of other congenital malformations and adverse outcomes (including reduced fertility).

The prevalence of selected pregnancy outcome risk factors in the life-style and medical history of the delivering population in north-western Russia.

OBJECTIVES: A population-based birth registry has been set up for the Arctic town of Moncegorsk in north-western Russia. This investigation describes the health status of the delivering population, including pregnancy history and the prevalence of obesity, infections, smoking and alcohol abuse during the pregnancy period. An overview of the occupations of the delivering population is also presented. METHODS: The birth registry contains detailed and verified information about the newborn, delivery, pregnancy and the mother for 21,214 births by women from Moncegorsk in the period 1973-97. RESULTS: Of the delivering women, 15.7% had experienced one or more spontaneous abortions, and 47.4% had at least one induced abortion. More than 9% had suffered pelvic inflammatory disease (PID) in their past. The local nickel company employed 9016 (42.5%) of the delivering women; of these 17% worked in production areas with exposures to compounds of nickel, among other hazards, and 38% are judged to have had possible, or probable, exposure of this type. CONCLUSION: Compared with the delivering population in Norway, that in Moncegorsk was younger and had a lower prevalence of obesity, diabetes and heavy smoking. The most worrisome findings were the high prevalence of a history of abortion and PID. A relatively high proportion of the women worked in physically demanding, or/and nickel-exposed occupations.

Epidemiology of Cardiovascular Malformations among Newborns in Monchegorsk (North-West Russia): a Register-Based Study.

BACKGROUND: Cardiovascular malformations (CVM) are one of the most prevalent groups of birth defects. Knowledge about the prevalence, distribution and survival in Russia has been limited. The aim of our study was to assess the perinatal prevalence, structure and risk factors for CVM among newborns in Monchegorsk (Murmansk Oblast, Russia) and the mortality among the affected newborns in the period 1973-2008. DESIGN AND METHODS: A register-based study on data from the Kola and Murmansk County Birth Registers. The study included 28,511 births. RESULTS: The registered perinatal prevalence was 3.0 per 1000 new-borns, with septal defects as the most prevalent. CVM was twenty times more prevalent among stillborn than live born, and one-third of the live born with a CVM died during the first week of life. The perinatal mortality rate with CVM was 442 per 1000 newborns. This indicator decreased over time. The mothers of newborns with a CVM were ten times more likely to have stillbirth in their anamnesis. The adjusted odds ratio between maternal smoking during pregnancy and CVM was 4.09 [95% confidence interval: 1.75-9.53]. CONCLUSIONS: The diagnosed perinatal prevalence was relatively low. A previous stillbirth by the mother was highly associated with being born with a CVM. An adjusted elevated risk was also observed among smoking mothers. Perinatal survival increased over time, but varied to a large extent between the different types of CVM. Significance for public healthCardiovascular malformation is one of the most common groups of birth defects. It is considered an important public health issue, as these malformations are the main cause of infant deaths in developed countries. Precise estimates about the prevalence and perinatal survival are needed to organise and plan health care for such newborns. Our study is the first report from the Russian Federation based on data from population-based birth registers.

How occupational health is assessed in mine workers in Murmansk Oblast.

OBJECTIVES: We aimed to describe how work exposure and occupational health is assessed for mine workers in Murmansk Oblast, Russia. STUDY DESIGN: A descriptive study based on current practice, laws and available literature. METHODS: The information and data were obtained from scientific publications, reports, regional and federal statistics, legal documents, through personal visits and on-site inspections. RESULTS: Several institutions are involved in these assessments, but all mine workers have been examined by specialists at one institution, which helps to ensure that the work is of stable quality and adds reliability value to the numbers. Workplace risks are assigned hazard grades, which influence the frequency of periodic medical examinations and salary levels. The examinations are aimed to diagnose latent or manifest occupational disease. This may lead to relocation to a workplace with lower exposure levels, free medical treatment, compensation and a lower pension age. CONCLUSIONS: Regulations and systems to protect the health of mine workers have more emphasis on control and repair than on prevention. Since relocation can lower the salary, some workers may under-report medical problems. To what degree this happens is unknown. The mining enterprises pay the medical service provider for periodic medical examinations, which could potentially weaken their independent role. This framework is important to understand when studying and assessing the health of working populations in the circumpolar region.

Spontaneous abortions among nickel-exposed female refinery workers.

A case-control study to investigate whether women employed in nickel-exposed work areas in early pregnancy are at elevated risk of spontaneous abortion (SA). Data about pregnancy outcome and maternal factors were obtained about each delivery and SA from women in selected work places. Each pregnancy record was assigned a categorical nickel (Ni) exposure rating according to the women's occupations at pregnancy onset. The guidelines were the water-soluble Ni subfraction of the inhalable aerosol fraction obtained by personal monitoring for nickel- and copper-refinery workers or/and measured urinary-Ni concentrations. The unadjusted odds ratio for the association between the maternal exposure to Ni and an SA for Ni-exposed women was 1.38 (95% confidence interval: 1.04-1.84), and the adjusted was 1.14 (0.95-1.37). In conclusion, there was no statistical association between maternal occupational exposure to water-soluble Ni in early pregnancy and the risk of self-reported SA. The findings do not exclude the possibility of a weak excess risk, or a risk in the first weeks of pregnancy.

The Kola Birth Registry and perinatal mortality in Moncegorsk, Russia.

BACKGROUND: A population-based birth registry has been set up for the Arctic town of Moncegorsk in north-western Russia. In this investigation, the quality and the content of the registry are assessed and the perinatal mortality (PM) rates in the period 1973-97 estimated. MATERIAL AND METHOD: Enrollment in the Kola Birth Registry (KBR) involved the retrospective inclusion of all births with at least 28 weeks of gestation in Moncegorsk in the period 1973-97. The data in the registry were assessed for data entry errors, completeness of data and population coverage. The annual PM rates were estimated for live- and stillborns with at least 28 weeks of gestation. RESULTS: The KBR contains detailed information about the newborn, delivery, pregnancy and mother for 21 214 births by women from Moncegorsk, covering at least 96% of all the births by the population in the period studied. No records were missing data for gender and birth date of the newborn, and more than 99.9% of the records contained data about gestational age and birthweight. Data concerning the mothers' employment were missing in 0.4% of the records. The annual PM rate fell from more than 20 to less than 10 deaths per 1000 births during this period. CONCLUSION: The KBR provides an extensive data source useful for case-control and register-based prospective studies, and constitutes the first such compilation in Russia. The homogeneity of the population in Moncegorsk makes it advantageous for epidemiological investigations. The PM rate in Moncegorsk was lower than the overall rate in Russia.