Preterm birth and exposure to air pollutants during pregnancy

Background

Research has shown that prenatal exposure to air pollutants may have a detrimental effect on fetal development, with the strength of the relationship depending on the effect being studied. The evidence to date, however, is insufficient to establish a direct causal link between such exposure and preterm delivery. This study evaluates the specific effect of prenatal exposure to NO₂ and benzene on preterm births.

Methods

The population under study comprised 785 pregnant women who formed part of the INMA cohort in Valencia, Spain (2003–2005). Multiple regression models were used for mapping outdoor nitrogen dioxide (NO₂) and benzene levels throughout the area. Individual exposure was assigned as the estimated outdoor levels at each woman’s home measured during each trimester as well as throughout the entire pregnancy. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated in order to assess the association between preterm birth and exposure to NO₂ and benzene. The shape of the exposure–response curve between air pollution and the risk of preterm birth was analyzed with a flexible approach, introducing a natural cubic spline for air pollution levels into the model.

Results

Pregnant women exposed to NO₂ and benzene have an increased risk of preterm birth. This risk was shown to be significant when women were exposed to NO₂ levels >46.2 μg/m³ during the second and third trimesters as well as throughout the entire pregnancy and to benzene levels >2.7 μg/m³ throughout the entire pregnancy.

Conclusion

These results suggest that maternal exposure to traffic-related air pollution is associated with preterm birth.     

孕期多环芳烃暴露对早产影响的研究进展

多环芳烃（PAH）是广泛存在于环境中的有毒污染物,可以通过呼吸道、消化道等多种方式进入人体。孕妇和新生儿是重要的敏感人群,相关的研究证据表明孕期PAH暴露可能是早产发生的重要原因,但具体的作用机制不是十分明确,可能与DNA损伤、氧化应激、全身炎症反应、内分泌干扰等有关。本文就孕期PAH暴露的影响因素和评价方法、孕期PAH暴露可增加早产的发生风险和可能的作用机制进行了综述。     

绒毛组织PAH - DNA加合物水平与孕早期胚胎停育的相关性

目的 探讨多环芳烃（PAH）暴露与孕早期胚胎停育的相关性,分析与胚胎停育有关的环境因素。方法 选取2019年3月- 2019年12月在山西医科大学第一医院产科诊断为胚胎停育的114例孕妇作为病例组,按照年龄、孕周、怀孕次数进行1∶1匹配,选择同期正常妊娠要求人工流产者114人为对照组。收集研究对象的基本信息及流产绒毛组织,检测绒毛组织PAH - DNA加合物含量。结果 病例组PAH - DNA加合物浓度高于对照组,差异具有统计学意义（t = 2.771,P = 0.007）。Kendall’s tau - b相关性分析显示PAH - DNA加合物水平与胎停育的发生呈正相关（Kendall’s tau - b = 0.129,P＜0.05）。条件logistic回归分析结果显示,中低暴露组、中高暴露组、高暴露组胎停育的发病风险分别为较低暴露组的5.052倍（OR = 5.052,95%CI: 2.064 - 12.367）、2.651倍（OR = 2.651,95%CI: 1.204 - 5.836）、2.536倍（OR = 2.536,95%CI: 1.103 - 5.832）。结论 孕妇PAH高暴露可能会增加胎停育的发病风险。     

母源性苯暴露对儿童急性淋巴细胞白血病影响的Meta分析

目的 探讨儿童急性淋巴细胞白血病(ALL)与母亲怀孕期间溶剂、油漆、石油接触及吸烟的关系.方法 检索Pubmed、Embase、the Cochrane library和Web of Science数据库中的相关文献,对母亲孕期接触苯和儿童急性淋巴细胞白血病的风险之间的优势比和95％的置信区间进行评估.结果 Meta分析结果显示母亲怀孕期间溶剂、油漆和石油暴露与儿童急性淋巴细胞白血病之间的关系差异有统计学意义,OR及95％ CI分别为[1.25 (1.09,1.45)],[1.23 (1.02,1.47)],[1.42 (1.10,1.84)].而母亲怀孕期间吸烟与儿童急性淋巴细胞白血病之间的关系差异无统计学意义,OR及95％ CI为[0.99 (0.93,1.06)].结论 母亲怀孕期间接触溶剂、油漆和石油与儿童患急性淋巴细胞白血病之间的关系差异有统计学意义,尚不能得出母亲怀孕期间吸烟与儿童急性淋巴细胞白血病的关系差异有统计学意义.母亲怀孕期间避免环境和职业接触苯可降低儿童急性淋巴细胞白血病的发病风险.     

我国儿童及母亲孕期接触农药与儿童白血病关系的Meta分析

目的 探讨我国儿童及母亲孕期接触农药与儿童白血病的关系.方法 对检索国内外数据库得到的12篇关于我国儿童及母亲孕期接触农药与儿童白血病关系的文献进行Meta分析.结果 儿童及母亲孕期接触农药可增加儿童患白血病的风险(OR=2.28,95％CI:2.01～2.59).按照地区、对照来源、样本量、调查时间、接触方式进行分组,亚组分析结果显示,各亚组儿童及母亲孕期接触农药均可增加儿童患白血病的风险.结论 儿童及母亲孕期接触农药是儿童白血病的危险因素.     

孕期父母环境危险因素暴露与儿童急性淋巴细胞性白血病风险关系分析

目的 探讨孕期父母接触可能引起儿童急性淋巴细胞性白血病（ALL）的环境危险因素。方法 选取2015年在天津市血液病医院就诊的179例ALL儿童为病例,同时选取136例正常儿童作为对照,进行病例对照研究;设计ALL发病的危险因素调查表,对所得的资料进行单因素和多因素非条件logistic回归分析。结果 单因素非条件logistic回归分析发现,儿童ALL发病与性别（OR=1.934,95% CI：1.225～3.054,P=0.005）、母亲既往流产史（OR=2.378,95% CI：1.437～3.934,P=0.001）、孕期二手烟暴露史（OR=1.837,95% CI：1.098～3.071,P=0.020）、患感冒（OR=1.728,95% CI：1.082～2.762,P=0.022）、服用解热镇痛药（OR=4.858,95% CI：1.824～12.944,P=0.002）、接触空气净化剂（OR=1.731,95% CI：0.972～3.082,P=0.043）、父亲职业性接触石油类产品（OR=2.007,95% CI：1.110～3.629,P=0.021）、怀孕期间居所装修（OR=2.506,95% CI：1.414～4.439,P=0.002）有关;多因素非条件logistic回归分析,ALL发病与性别（OR=2.037,95% CI：1.254～3.308,P=0.004）、母亲既往流产史（OR=2.078,95% CI：1.232～3.503,P=0.006）、怀孕期间居所装修（OR=1.689,95% CI：1.046～2.726,P=0.032）、母亲孕期感冒（OR=1.677,95% CI：1.018～2.764,P=0.043）、父亲职业性接触石油类产品（OR=1.988,95% CI：1.069～3.696,P=0.030）有关。结论 性别、母亲孕前流产史、怀孕期间装修史、母亲孕期感冒史、父亲职业性石油类产品接触史5项指标可能为引起儿童ALL的危险因素。     

Risk of leukemia as a result of community exposure to gasoline vapors: a follow-up study

Objectives

To assess the temporal and spatial relationship of risk for total leukemia and AML (acute myelogenous leukemia) among community residents of an area in northeastern (NE) Pennsylvania (PA) affected by the Tranguch Gasoline Spill which occurred in the early 1990s.

Methods

Standardized incidence ratios (SIR) were calculated for total leukemia and AML among 625 residents affected by the gasoline spill in relation to both PA and local county cancer incidence rates. The risk of total leukemia and AML among the gasoline exposed population was evaluated for the period prior to the spill, 1985–1989; during the time surrounding the spill, 1990–1994; and for a period subsequent to the spill, 1995–2001.

Results

The incidence of total leukemia and AML was significantly elevated subsequent to the spill for the entire period 1990–2001 and was highest for the period 1995–2001, whether comparison was made to PA or local county leukemia rates. Based on comparison to PA rates, the SIRs for total leukemia and AML were 7.69 (95% CI=1.58–22.46) and 11.54 (95% CI=2.38–33.69) for the 1995–2001 period, respectively. Prior to the spill, 1985–1989, and during the period of the spill, 1990–1994, no cases of leukemia were identified among the affected residents.

Conclusions

These results suggest a possible association between chronic low level benzene exposure and increased risk of leukemia among residents of the Tranguch Spill Site in NE PA. Our study provides additional support to the growing body of evidence implicating low level benzene exposure and cancer risk. We recommend that other communities contaminated with gasoline vapor through leaking underground storage vessels be monitored for elevated risk of leukemia.     

儿童白血病化疗后并发败血症的临床分析及治疗

目的:探讨儿童急性白血病化疗后并发败血症的发生、治疗和预后因素。方法:回顾性分析30例患儿化疗后并发败血症的临床特点。结果:主要病原菌为革兰氏阴性杆菌,其中铜绿假单胞菌最多,其次为大肠埃氏希菌。亚胺培南(泰能)为革兰氏阴性杆菌最敏感抗菌素,万古霉素为革兰氏阳性菌最敏感抗菌素。化疗时中性粒细胞总数持续减低的败血症患儿的病死率高。并发败血症时患儿血清C反应蛋白(CRP)的水平明显升高。结论:革兰氏阴性杆菌为儿童急性白血病化疗后并发败血症的最常见病原菌。中性粒细胞减低的持续时间与败血症的发生与预后有密切关系。临床上遇到可疑的败血症患儿应尽早查血培养和CRP,同时给予经验性抗感染治疗。亚胺培南为儿童急性白血病化疗后粒细胞减少并发严重感染时十分有效的抗生素。     

Risk of lung cancer in workers producing stainless steel and metallic alloys

Objectives: The mortality of workers involved in the production of stainless and alloyed steel from 1968 to 1992 was studied, in order to investigate the risk of lung cancer due to exposure to metals, i.e. iron oxides, chromium and/or nickel compounds. Methods: The study design was a historical cohort mortality study and a nested case-control study concerning lung cancer. Standardized mortality ratios (SMRs) were computed using regional mortality rates as an external reference for comparing observed and expected numbers of deaths, adjusting for age, sex and calendar time. Conditional logistic regression was used to estimate odds ratios (ORs). Occupational exposure was assessed through the complete job histories of cases and controls and a specific job-exposure matrix. Results: The cohort comprised 4,288 male and 609 female workers. The observed overall mortality was significantly lower than expected [649 deaths; SMR = 0.91; 95% confidence interval (CI) 0.84–0.98]. No significant SMR was observed for mortality from lung cancer (54 deaths; SMR = 1.19; CI 0.88–1.55). The case-control study was based on 54 cases and 162 individually matched controls. Smoking habits were available for 71%. No lung cancer excess was observed for exposure to (1) metals and/or their compounds, i.e. iron (OR = 0.94, CI 0.48–1.86), chromium and/or nickel (OR = 1.18, CI 0.62–2.25), and cobalt (OR = 0.64, CI 0.33–1.25), (2) acid mists (OR = 0.43, CI 0.17–1.10), and (3) asbestos (OR =  1.00, CI 0.54–1.86). With respect to exposure to polycyclic aromatic hydrocarbons (PAHs) and silica, which are often found together in workplaces, (1) high and statistically significant lung cancer excesses were observed, the ORs being 1.95 (CI 1.03–3.72) and 2.47 (CI 1.28–4.77) respectively, (2) quantitative exposure parameters revealed upward trends reaching statistical significance (P < 0.05), and (3) adjustments for tobacco consumption did not reveal any confounding factors from smoking. Conclusion: This study failed to detect any relationship between lung cancer and exposure to iron, chromium, nickel and/or their compounds. High and statistically significant relative risks, along with increasing trends, were observed for simultaneous exposure to PAHs and silica. Received: 12 April 1999 / Accepted: 2 October 1999     

Indoor exposure to polycyclic aromatic hydrocarbons and carbon monoxide in traditional houses in Burundi

Objectives: Wood combustion is used as a major energy source in African countries and could result in indoor, pollution-related health problems. This exploratory study was undertaken to estimate polycyclic aromatic hydrocarbon (PAH) and carbon monoxide exposure in individuals living in traditional rural houses in Burundi. Methods: Standard methods were used to determine indoor air concentrations of 12 PAHs, and carbon monoxide. The urinary excretion of 1-hydroxypyrene (1-OHP) was measured in occupants of traditional houses, and compared with that of individuals living in the town of Bujumbura, the capital of Burundi. Results: Mean airborne concentration of four volatile PAHs, naphthalene, fluorene, phenanthrene and acenaphthene, exceeded 1 μg/m³, and that of benzo(a)pyrene was 0.07 μg/m³. Naphthalene was by far the main PAH contaminant, with a mean concentration (±standard deviation) of 28.7 ± 23.4 μg/m³, representing on average 60–70% of total PAH concentration. Carbon monoxide mean concentration (±standard deviation) was 42 ± 31 mg/m³, and correlated with total PAH concentration. Geometric mean urinary 1-OHP excretion (range) in people living in traditional houses was 1.50 (0.26–15.62) μmol/mol creatinine, a value which is on average 30 times higher than that of people living in the capital (0.05 (0.009–0.17) μmol/mol creatinine). Conclusions: It appears that the substantially high concentrations of the studied contaminants constitute a potential health hazard to the rural population of Burundi. Received: 15 July 1999 / Accepted: 20 November 1999     

Inhalation and dietary exposure to polycyclic aromatic hydrocarbons and urinary 1-hydroxypyrene in non-smoking university students

Objective To examine which exposure pathway, dietary or inhalation, contribute more to the exposure to, and/or internal dose of, polycyclic aromatic hydrocarbons (PAHs) of non-smoking Japanese. Methods Duplicated diet, personal air samples and 24-h urine were collected from14 non-smoking male university students without occupational exposure and the concentrations of PAHs in diet and air and that of 1-hydroxypyrene (1-OHP) in urine were measured with HPLC-fluorescence detector. Results Daily dietary exposure contributed more than 90% of the total (diet + inhalation) daily exposure level for pyrene (diet/inhalation: 757/1.2 ng/day), benzo[k]fluoranthene (25/1.7 ng/day) and benzo[a]pyrene (91/2.1 ng/day). Urinary excretion of 1-OHP (median: 37 ng/day) was statistically significantly correlated only with dietary PAHs exposure level but not with inhalation. Conclusion Countermeasures to lower PAHs levels in atmosphere has been successful in Japan and more attention should be directed to dietary exposure to PAHs for reducing cancer risk in general population.     

Spontaneous pregnancy loss in humans and exposure to arsenic in drinking water

Maternal exposure to high concentrations of inorganic arsenic (iAs) in naturally contaminated drinking groundwater sources has been associated with an increased risk for the spontaneous loss of clinically recognized pregnancies in several epidemiologic studies. Whereas a large worldwide population depends on drinking groundwater sources with high levels of iAs contamination, in quantities exceeding 10 parts per billion (ppb), an even larger population is likely to be exposed to mild-moderate drinking groundwater iAs contamination, in quantities <10ppb. Only a single epidemiologic study to date has considered spontaneous pregnancy loss in association with consumption of drinking water with mild-moderate iAs contamination; the vast majority of published studies of spontaneous loss addressed populations with substantial exposure. The aim of this review is to evaluate the published literature to assess the plausibility for a causal association between exposure to iAs-contaminated drinking water and the spontaneous loss of clinically recognized pregnancy. In spite of numerous methodologic limitations resulting from circumstance or design, a consistent pattern of increased risk for loss is suggested by the epidemiologic literature. Moreover, these study results are corroborated by a large number of experimental studies, albeit usually conducted at concentrations exceeding that to which humans are exposed via contaminated drinking water. In this review, we discuss sources of human iAs exposure, highlight several experimental studies pertinent to a possible causal link between iAs and spontaneous pregnancy loss in humans, and provide a critical review of published epidemiologic studies of pregnancy loss and drinking water iAs exposures, and their limitations. Based on a review of the published literature, we recommend the future conduct of a two-stage comprehensive prospective study of low-moderate iAs drinking water exposure and spontaneous pregnancy loss.     

Urinary 1-naphthol and 1-pyrenol as indicators of exposure to coal tar products

Chemical exposure of assemblers handling creosote-impregnated wood and of a single worker chiselling coal tar pitch layer was assessed by measuring airborne naphthalene and various polycyclic aromatic hydrocarbons (PAHs), and by measurement of urinary excretion of 1-naphthol and 1-pyrenol. The sum concentration of PAHs and of 4–6 aromatic ring-containing PAHs were high, 440 g/m³ and 290 g/m³, respectively, when chiselling. In the assembler's workplace, the PAH concentrations were about 1/50 of this value. Regarding airborne naphthalene concentrations the situation was reversed (assemblers, 1000 g/m³; chiseller, 160 g/m³). Correspondingly, the assemblers' urinary 1-napthol concentrations were 15–20 times higher than those of the chiseller. The urinary 1-pyrenol concentration of the chiseller was 2–4 times higher than among the assemblers. As the estimated pyrene inhalation doses among the assemblers could account for only about 2%–25% of the 24-h pyrenol excretion in urine, the skin was presumably the main route of uptake. For an assessment of the exposure to PAHs, air measurements, monitoring of metabolites in urine and preferably also data on the composition of the skin-contaminating product are needed.     

北京市昌平区大气颗粒物中多环芳烃暴露及人群健康风险评价

目的了解北京市昌平区大气颗粒物PM_(10)、PM_(2.5)及多环芳烃(PAHs)的污染水平,分析PAHs的污染来源,并进行人群健康风险评估。方法于2015年1—12月用大气采样器采集北京市昌平区大气样品,分别用称重法和高效液相色谱法检测大气PM_(10)、PM_(2.5)质量浓度和16种PAHs浓度;利用比值法分析PAHs的污染来源,并对其人群健康风险进行评估。结果 2015年北京市昌平区大气PM_(10)和PM_(2.5)的质量浓度范围分别为7.8~343.0μg/m~3和6.3~344.3μg/m~3,年均浓度分别为97.0、78.6μg/m~3;PAHs浓度范围为2.4~383.0 ng/m~3,年均浓度为87.8 ng/m~3。4环PAHs浓度与5、6环PAHs浓度比值范围为0.15~1.38。PAHs的等效毒性浓度以夏季最低(0.354 ng/m~3),冬季最高(29.816 ng/m3)。PAHs对成人及儿童的终身致癌超额风险分别为9.68×10~(-6)和6.14×10~(-6)。结论北京市昌平区大气颗粒物浓度高于GB 3095—2012《环境空气质量标准》二级标准,PAHs污染主要来自本地污染;PAHs对成人的终身致癌风险高于儿童,但两者均处于可接受水平。     

Biological monitoring of occupational exposure to polycyclic aromatic hydrocarbons (PAH) by determination of monohydroxylated metabolites of phenanthrene and pyrene in urine

Objectives The aim of our study was to assess individual polycyclic aromatic hydrocarbon (PAH) exposure of workers coming from three different industrial branches by several parameters of external and internal exposure. By analysing the relationships between those markers the suitability of individual parameters [e.g. monohydroxylated phenanthrene (Phe) metabolites] for exposure surveillance should be evaluated. Methods The total study population consisted of 255 male workers (age: 19-62, mean: 39.61 years), who were employed in coke production (n = 40), production of graphite electrodes and special carbon products (92), or production of refractory materials (123), respectively. For each worker external PAH exposure was determined by personal air sampling of 16 PAH, including Phe, pyrene (Pyr) and benzo[a]pyrene (BaP). For determination of internal PAH exposure the excretion of the PAH metabolites 1-, 2 + 9-, 3-, 4-hydroxyphenanthrene and 1-hydroxypyrene was measured in post-shift urine samples of all workers. Results In the total study population median total PAH exposure and exposure to BaP were 30.62 and 0.27 μg/m3, respectively. A calculation of PAH profiles resulted in substantial branch-related variations with Phe being a major component. Considering all branches the median excretions of 1-hydroxypyrene and hydroxyphenanthrenes (sum) were 6.68 and 11.22 μg/g creatinine. A correlation analysis yielded a good correlation between total ambient PAH exposure and excretion of hydroxyphenanthrenes in urine (r = 0.662; P < 0.01), but no significant correlation between Phe metabolites and the carcinogenic BaP. For 1-hydroxypyrene and BaP a weak but significant association was found (r = 0.235; P < 0.01). Conclusions Considering the results of the correlation analysis hydroxyphenanthrenes in urine should reflect an uptake of lowly condensed volatile PAH rather than an incorporation of highly condensed PAH like BaP which should be reflected better by 1-hydroxypyrene. Therefore, the determination of hydroxyphenanthrenes in addition to the well-established marker 1-hydroxypyrene could offer some further information about the exposure situation at a particular work place.     

Exposure to polycyclic aromatic hydrocarbons (PAHs) and bladder cancer: evaluation from a gene-environment perspective in a hospital-based case-control study in the Canary Islands (Spain)

Background:

Exposure to polycyclic aromatic hydrocarbons (PAHs) has been linked to bladder cancer.

Objective:

To evaluate the role of PAHs in bladder cancer, PAHs serum levels were measured in patients and controls from a case-control study.

Methods:

A total of 140 bladder cancer patients and 206 healthy controls were included in the study. Sixteen PAHs were analyzed from the serum of subjects by gas chromatography–mass spectrometry.

Results:

Serum PAHs did not appear to be related to bladder cancer risk, although the profile of contamination by PAHs was different between patients and controls: pyrene (Pyr) was solely detected in controls and chrysene (Chry) was exclusively detected in the cases. Phenanthrene (Phe) serum levels were inversely associated with bladder cancer (OR = 0·79, 95%CI = 0·64–0·99, P = 0·030), although this effect disappeared when the allelic distribution of glutathione-S-transferase polymorphisms of the population was introduced into the model (multinomial logistic regression test, P = 0·933). Smoking (OR = 3·62, 95%CI = 1·93–6·79, P<0·0001) and coffee consumption (OR = 1·73, 95%CI = 1·04–2·86, P = 0·033) were relevant risk factors for bladder cancer.

Conclusions:

Specific PAH mixtures may play a relevant role in bladder cancer, although such effect seems to be highly modulated by polymorphisms in genes encoding xenobiotic-metabolizing enzymes.     

大气细颗粒物多环芳烃暴露对健康人尿中羟基代谢物和氧化应激水平的影响

目的 研究大气颗粒物（PM2.5）及多环芳烃暴露与人体内羟基代谢物的关系,并探讨其对健康人群氧化应激水平的影响。方法 招募46名在校大学生,采用定组研究的方法,于2015夏季和冬季对招募对象进行2次随访,采集研究对象尿样并测定尿中羟基代谢物和8 - 羟基脱氧鸟苷。结果 PM2.5、∑PAHs浓度和温度在夏季和冬季的差异有统计学意义（P＜0.05）;而相对湿度（RH）间差异无统计学意义;在夏季时,2 - OHFlu、3 - OHPhe、1 - OHPhe和1 - OHPyr浓度依次为0.25、0.16、0.13、0.08 μmol/mol Cr;而冬季浓度依次为0.63、0.73、0.40、0.42 μmol/mol Cr,经配对t检验,2组间差异均有统计学意义。而8 - OHdG虽然在冬季略高于夏季,但2组间差异无统计学意义。经Spearman 相关分析,4种OH - PAHs与∑PAHs均有较强相关性,8 - OHdG、PM2.5、∑PAHs及OH - PAHs无相关性。结论 细颗粒物PM2.5及多环芳烃暴露对人体羟基代谢物水平有影响,冬季羟基代谢物水平高于夏季,而对8 - OHdG的影响不显著。     

1-Hydroxypyrene in human urine after exposure to coal tar and a coal tar derived product

Summary A method for isolating 1-hydroxypyrene from urine is described. The presence of 1-hydroxypyrene in urine was identified by fluorescence excitation and emission scanning after HPLC-separation. 1-Hydroxypyrene could be detected in the urine of rats following oral administration of as little as 0.5 g pyrene. The dose-dependence of 1-hydroxypyrene in urine was evident after a wide range of pyrene dosing. After therapeutical coal tar treatment of dermatological patients the enhanced excretion of 1-hydroxypyrene was highly significant. Employees of a creosote impregnating plant showed an excretion pattern of 1-hydroxypyrene which could be related to their work. 1-Hydroxypyrene in urine of non-exposed people was very low, but detectable. It is suggested that the method reported is suitable for the assessment of uptake of man to pyrene, a compound that is commonly present in work environments which are associated with pollution of polycyclic aromatic hydrocarbons.     

Duration of pregnancy in relation to seafood intake during early and mid pregnancy: prospective cohort

We examined the association between exposure to seafood intake during two periods of pregnancy on the one hand and risks of preterm delivery and postterm delivery on the other. In a prospective cohort of 8729 pregnant Danish women, we assessed frequency of fish meals during the first and second trimester of pregnancy by questionnaires completed around gestation weeks 16 and 30, respectively. When fish intake was based solely on intake reported for the early period of pregnancy, mean gestation length was shorter by 3.91 (95% CI: 2.24–5.58) days and odds of preterm delivery were increased 2.38 (1.23–4.61) times in those who never consumed fish (n = 308) vs. those who consumed both fish as main meal and fish in sandwiches at least once per week (n = 785). These measures were similar when fish intake was based solely on intake reported for mid-pregnancy. In the subgroup of women reporting same intake in the two trimesters, those who never consumed fish (n = 165) had 8.57 (5.46–11.7) days shorter mean gestation and 19.6 (2.32–165) times increased odds of preterm delivery, compared to high fish consumers (n = 127); odds of elective and postterm delivery were reduced by a factor 0.33 (0.11–1.02) and 0.34 (0.12–0.95), respectively, in zero fish consumers. All analyses were adjusted for potential confounding by factors such as maternal smoking, height, and prepregnant weight. We conclude that never consuming fish in the first two trimesters of pregnancy was an extremely strong risk factor for preterm delivery but was also associated with reduced risks of elective delivery and postterm delivery.     

High human exposure to pyrene (polycyclic aromatic hydrocarbon) in Kinshasa,a capital of the Democratic Republic of Congo

Background

Data on human exposure to chemicals in Africa are scarce. A biomonitoring study was conducted in a representative sample of the population in Kinshasa (Democratic Republic of Congo) to document exposure to polycyclic aromatics hydrocarbons.

Methods

1-hydroxypyrene (1-OHP) was measured by HPLC fluorescence in spot urine samples from 220 individuals (50.5% women), aged 6–70 years living in the urban area and from 50 additional subjects from the sub-rural area of Kinshasa. Data were compiled as geometric means and selected percentiles, expressed without (μg/L) or with creatinine adjustment (μg/g cr). Multiple regression analyses were applied to factors (creatinine, grilled meat habits and smoking habits) influencing 1-OHP (stepwise procedure, criteria: probability F to enter ≤ 0.05 and probability F to remove ≥ 0.10).

Results

According to the regression models, creatinine, grilled meat habits and smoking habits contribute to explain 45% of the variation in population’s urinary 1-OHP by the environmental exposure. Overall, living in urban area of Kinshasa was associated with increased levels of 1-OHP in urine as compared to a population living in the sub-rural area [GM: 1.8 μg/L (n = 220) versus 1.4 μg/L (n = 50), p < 0.01] as well as compared to the reference values from databases involving American or German populations.

Conclusion

This study reveals the high pyrene (PAH) exposure of the Kinshasa population. However, more work, with a rigorous design in the exposed population (monitoring of air concentrations and identifying other sources of pyrene –PAH exposure), is needed to establish further documentation.