Cancer Risk Due to the Natural Radioactivity in Cigarette Tobacco

Thirty-one samples of cigarettes have been collected from local markets of different types of origins. The samples were selected according to a survey distributed to smokers by paper and digital survey to see the most heavily traded among smokers and in addition to a number of questions to see how the awareness and the culture of smokers in diseases caused by smoking and considered this study the first survey in Iraq. The aim of this research is to assess the number of cancer cases due to cigarette smoking. Through the use of High-Purity Germanium system (HPGe) (efficiency 40%) we determinated the radionuclides in cigarette tobacco. The average values were (14.86 ± 3.76, 10.84 ± 3.13, 1050.64 ± 47.57) Bq/kg for Ra-226, Th-232 and K-40, respectively, and the excess lifetime of cancer risk values ranged from 0.54 to 130 at average of 76 per million person per year. Raeq values varied from 18.50 to 87.21.4 Bq/kg with an average value of 39.51 Bq/kg for tobacco samples. The annual effective dose (HE) varies from 16.38 μSv/y to 44.69 μSv/y with an average value of 24.97 μsv/y. The Annual Gonadal Dose Equivalent (AGDE) varies from 0.3 to 0.64 (mSv/y) with an average value of 0.42 for all tobacco samples under investigation.

Health Risks Associated with Heavy Metals in Fine Particulate Matter: A Case Study in Delhi City, India

The concentrations of twenty five heavy metals adsorbed to fine fraction of particulate matter, PM2.5 (d ≤ 2.5 μm) have been experimentally analysed at a sampling site located at the kerbside along a National Highway in Delhi city, India. The sampling has been carried out for 12-hour using Ecotech Intruments, APM550. The PM2.5 has been collected on PTFE filter papers for the winter season. Later, the filter papers have been analysed for various heavy metal concentrations using ED-XRF. It has been observed that the metals concentrations are in this trend: Si > K > S > Ca = Fe > Zn = Pb > Br. it is observed that Si has high co-relation with Ca, Fe and K, which may be due to crustal origin of all three elements;while S, Br and Pb may be from vehicular exhaust emissions and/or abrasions due to brake and tyre wear. The potential health risks associated with different carcinogenic heavy metals have also been calculated. One of the health risk indicators, the excess cancer risk (ECR), is found to be in the order as As > Cd > Pb > Cr > Ni.

Health Risk Assessment for Bromate (BrO₃^–) Traces in Ozonated Indian Bottled Water

For this study, bromide and bromate ions in various commercial brands of Indian bottled water samples were estimated using ion chromatography. The measured mean concentration of bromide and bromate ions in water samples was found to be 28.13 μg/L and 11.17 μg/L respectively. The average level of bromate in Indian bottled water was found to be slightly higher (~ 12%) than the acceptable limits (10 μg/L) recommended by USEPA (US Environmental Protection Agency). Though, kinetically, it is predicted that 62.5% (6.25 μg/L) of bromide in bottled water is needed to convert into bromate upon ozonation to exceed the minimum acceptable limits, but the average formation of bromate determined to be only 26.77% of the predicted concentration. Bromate concentration in bottled water showed a strong correlation with bromide suggesting that its formation in water is very much influenced and controlled by bromide content. The objective of the present study was to determine the BrO3–) content of commercially available different brands of bottled drinking water in India and to estimate the health risks to population due to ingestion. Results of estimated excess cancer risk and chemical toxicity risk to Indian population due to ingestion of bottled water were presented and discussed.

Investigation of the Radiological Risk of Farmlands and the Transfer Factor from Soil to Crops in Jalingo and Wukari L.G.A of Taraba State, Nigeria

The activity concentrations of radionuclides, absorbed dose rate, excess lifetime cancer risk, and soil-to-plant transfer factor have been evaluated in soil and crop samples from Jalingo and Wukari Local Government Area of Taraba State, Nigeria. The activity concentrations were determined with the aid of High Purity Germanium detector. The absorbed dose and excess lifetime cancer risk were evaluated and forecasted for 60 years using the ResRad off-site model. The average activity concentration of 40K, 232Th, and 238U in the soil samples were 633.13, 141.15, and 71.20 Bq·kg-1 respectively, for the Jalingo study area, and while that of the Wukari study area was;199.21, 87.23, and 25.37 Bq·kg-1 respectively. The average soil-to-plant transfer factors for 40K, 232Th, and 238U were 0.51, 0.10, and 0.27 respectively for the Jalingo study area while that of Wukari are 0.40, 0.57, and 0.74 respectively. The mean annual effective dose equivalent for the study area is higher than the world average of 0.07 mS·vy-1. The excess lifetime cancer risk for the study areas has values that are higher than the safety limit. The ResRed model showed that direct radiation from the crops is the major contributor to excess cancer risk among other pathways. The radiological hazard indices reveal health risks to farmers, especially in the Jalingo area.

Toxicity of Radon-222 in Groundwater across Keana in Nasarawa,Nigeria

The most common supply of freshwater for drinking,irrigation,and other domestic uses is groundwater;however,because of increased radon concentrations brought on by mining activities,its quality is still a severe concern.Using a liquid scintillation detector,this study investigated the radon content,its related toxicity,and its risk to human health in the groundwater of the Keana in Nasarawa,Nigeria.Ten(10)borehole samples and five(5)well samples totaling fif­teen(15)groundwater samples were taken.The results showed that the average radon concentration in water samples from Keana was 2.25 Bq/L.The mean annual effective dosage(ingestion)for adults and children in Keana was 0.016 mSv/y and 0.027 mSv/y,respectively.In Keana,the additional lifetime cancer risk per adult was 5.65×10^(-5),and per child,it was 8.79×10^(-5).The study’s radon concentration was lower than the benchmark of 11.1 Bq/L established in 1991 by the Nigerian Standard Organization and the US Environmental Protection Agency.The results of this study indicate that the level of radon is safe;as a result,people can continue farming and other activities.To reduce the risk of cancer,however,more research could be done in the area.Further research should be done by looking at additional sources in the study area in order to cover the entire zone.Further investigation should be carried out both during the dry and wet seasons because radon concentrations in groundwater alter over time due to dilution by recharge from rainfall.

肝硬化后肝癌患者的临床特征及肝硬化进展为肝癌的危险因素

目的分析肝硬化后肝癌的临床特征及肝硬化进展为肝癌的危险因素。方法回顾性分析200例肝硬化患者的临床资料,其中发生癌变100例(观察组),未发生癌变100例(对照组)。采用多因素Logistic回归模型分析肝硬化进展为肝癌的危险因素。结果 100例肝硬化后肝癌患者以年龄≥50岁、男性为主,乙型病毒性肝炎是最常见的病因。年龄≥50岁、男性、酗酒>10年、HBV感染均是肝硬化进展为肝癌的危险因素(均P<0.05)。结论肝硬化后肝癌患者以中老年人、男性为主,病因主要是乙型病毒性肝炎;年龄≥50岁、男性、酗酒>10年、HBV感染的肝硬化进展为肝癌的风险增大。

住宅室内氡浓度的时间空间变化对肺癌危险度的影响

最近在甘肃进行的研究表明 ,居室内氡浓度的增加会导致肺癌危险度增高 ,这与以往进行的汇总分析和其他居室研究的综合分析结果一致 (王作元 ,等 .美国流行病学杂志 ,2 0 0 2 .1 5 5 :5 5 4)。室内氡浓度产生的剂量用过去 3 0年中的氡浓度表示 ,这在暴露量方面会有一定程度的不确定度 ,有可能降低对肺癌危险度的估计。我们进行了一项为期三年涉及 5 5户居民的辅助研究 ,目的是找出室内氡水平时间、空间变化模型 ,并对氡致肺癌危险度的估计进行调整。氡浓度的时间变化是产生不确定度的最大来源 ,对室内氡进行连续几年的观测以找出其变化原因和规律很有必要。不确定度的调整使肺癌附加比值比 (excessoddsratio)估算值增加 5 0 %～ 1 0 0 %。说明用类似剂量方法进行的室内氡研究也可能低估了氡致肺癌效应。

Health Effects of Radiation Exposure to Human Sensitive Organs across Some Selected Mining Sites of Plateau State,Nigeria

The association of radiation with matter,being it from external means(i.e.external sources)or from internal pollution of the body by toxic substances,can pose biological hazard which may show the clinical symptoms later.The nature and extent of these symptoms and the time they take to appear are a function of the amount of radiation absorbed and the rate at which it is received.This study aimed at assessing the health effects of radiation exposure to human sensitive organs across some selected mining sites of Plateau State Nigeria.Finding of this study have revealed that the mean Dorgan values for the lungs,ovaries,bone marrow,testes,kidney,liver and whole body for different mining points of Plateau State are 0.29 mSv/y,0.26 mSv/y,0.31 mSv/y,0.36 mSv/y,0.28 mSv/y,0.21 mSv/y and 0.30 mSv/y respectively.From the findings presented,it can be concluded that the background radiation in Plateau State is not an issue of health concern in regards to sensitive organs and may not course immediate health effect except when accumulated over long period of time which may cause cancer to the indoor members on approximately seventy years of exposure.

使用不同修正时某铀矿矿工氡致肺癌超额相对危险系数估算

目的探讨某铀矿矿工氡暴露致肺癌风险的修正因素,估算该铀矿职业氡暴露人群氡致肺癌超额相对危险(ERR)系数。方法采用回顾性队列研究方法,以1958—2018年湖南省某铀矿从事井下作业时间≥1年的男性矿工为研究对象,采用Possion回归模型对不同修正时该矿矿工氡致肺癌ERR系数进行初步估算。结果本队列共包含4851名铀矿工,1958—2018年因肺癌死亡187例,累计随访207251人年。无修正因素的氡致肺癌的ERR系数估计值为0.21%/工作水平月(WLM)(95%置信区间为0.04%/WLM~0.27%/WLM)。在最终选定的Possion回归模型中,氡致肺癌的指数修正因素为自暴露以来时间和暴露率。在该模型中,当自暴露以来时间为45年、暴露率为0.14 WL时,ERR系数估计值为1.73%/WLM(95%置信区间为0.36%/WLM~3.11%/WLM);自暴露以来时间每增加10年时ERR减少约60.00%,暴露率每增加1.00 WL时ERR增加约30.00%。结论该矿铀矿工氡致肺癌的修正因素为自暴露以来时间和暴露率;据此初步估算该铀矿职业氡暴露人群氡致肺癌ERR系数估计值为1.73%/WLM(95%置信区间为0.36%/WLM~3.11%/WLM)。

北京市某城区大气PM_(2.5)中苯并[a]芘暴露的人群致癌风险评估

目的了解北京市某城区采暖季大气PM_(2.5)中苯并[a]芘的污染水平和人群致癌风险。方法于2016年12月—2017年2月采集北京市某城区每日PM_(2.5)样品,采用高效液相色谱—荧光检测器法测定PM_(2.5)上苯并[a]芘浓度,评估不同污染天气过程的污染水平下,男性、女性、总人群因吸入苯并[a]芘导致的人群终生超额致癌风险和预期寿命损失。结果苯并[a]芘日均质量浓度中位数为5.20(2.13,11.05)ng/m^3。重污染天气过程的苯并[a]芘日均质量浓度中位数为12.90(5.76,21.98)ng/m^3,是非重污染天气过程3.90(1.13,8.92)ng/m^3的3.3倍,差异有统计学意义。北京市某城区男性在重污染天气过程、非重污染天气过程以及研究期间的苯并[a]芘暴露浓度下,IUR取值为1.1×10^(-6)(ng/m^3)^(-1)时,超额致癌风险分别为9.42×10^(-6)、2.85×10^(-6)和3.80×10^(-6),预期寿命损失分别为55.1、16.7和22.2 min;IUR取值为8.7×10^(-5)(ng/m^3)^(-1)时,超额致癌风险分别为7.46×10^(-4)、2.25×10^(-4)和3.01×10^(-4),预期寿命损失分别为4359、1318和1757 min。北京市某城区女性在不同污染天气过程的苯并[a]芘浓度暴露下,IUR取值为1.1×10^(-6)(ng/m^3)^(-1)及8.7×10^(-5)(ng/m^3)^(-1)时,超额致癌风险均超出10^(-6)的可接受水平,预期寿命损失分别为62.0、18.7、25.0 min和4903、1482和1976 min。结论基于2016年冬季苯并[a]芘浓度数值的健康风险评估结果说明,不同天气过程的苯并[a]芘暴露水平对北京市某城区人群具有潜在致癌风险。重污染天气过程苯并[a]芘暴露导致的超额致癌风险和预期寿命损失是非重污染天气过程的3.3倍。女性的超额致癌风险略低于男性,但预期寿命损失略高于男性。

阳江天然放射性高本底辐射慢性照射与实体癌超额危险

目的 估算阳江高本底辐射慢性照射可能导致的实体癌超额相对危险。方法 基于自然村室内、外环境剂量和性别年龄别居留因子 ,估算研究群组每一个成员的累积剂量。假定剂量与癌症危险间存在线性关系 ,利用 1979～ 1995年的癌症死亡率资料 ,按照Poisson模型计算超额相对危险。结果 全部实体癌超额相对危险 (ERR)为 - 0 11(95 %CI,- 0 6 7,0 6 9) Sv。肝癌、鼻咽癌、肺癌和胃癌等前 4位癌症的ERR(95 %CI) Sv分别为 - 0 99(- 1 6 0 ,0 10 ) ,0 10 (- 1 2 1,3 2 8) ,-0 6 8(- 1 5 8,1 6 6 )和 - 0 2 7(- 1 37,2 6 9)。结论 未发现实体癌超额相对危险与剂量有关。

阳江高本底地区恶性肿瘤死亡调查1987～1995年资料分析

目的本项研究是高本底辐射研究组的一项专题，始于１９７２年，旨在探索平均年有效剂量为６４ｍＳｖ的阳江天然放射性高本底辐射照射的致癌危险。１９９１年起中日两国科学家合作继续研究，以累积更多观察人年数，提高统计学精度，并检验以往研究的可重复性。方法合作研究后所获１９８７～１９９５年恶性肿瘤死亡资料是通过回顾性调查或／和前瞻性调查从定群队列中获得。恶性肿瘤死亡现场调查分为队列成员追踪和死因确认两步骤。按外照射年剂量水平，将高本底人群分为高、中、低剂量３个组，以进行内比较。高本底地区３个剂量组与对照组之间的比较采用相对危险（ＲＲ）。ＲＲ和超额相对危险（ＥＲＲ）系数及其９５％置信区间（ＣＩ）计算应用Ｅｐｉｃｕｒｅ中ＡＭＦＩＴ程序。结果１９８７年１月１日定群观察起点人口为１０６５１７人，至１９９５年共累积观察９２６２３８人年，期间共死亡５１６１人，其中恶性肿瘤死亡５５７例。整个高本底地区经性别年龄组调整的全部恶性肿瘤的ＲＲ（９５％ＣＩ）为０９６（０８０，１１５）。就部位别恶性肿瘤而论，白血病、鼻咽癌、食管癌和小肠癌的ＲＲ大于１，而胃癌、肝癌、肺癌、女性乳腺癌、甲状腺癌和淋巴肉瘤的ＲＲ小于１，但差异均无显著性。对全?

氡致肺癌危险新模型的应用

目的对氡致肺癌的超额相对危险新模型进行研究与应用。方法在理论研究的基础上,采用三次样条插值法和对数线性内插法计算不同情况下的ERR1wlm值。结果给出了依据NIH 03-5387模型计算氡致肺癌病因概率的方法和过程。结论验证表明,本文所给出的病因概率计算方法操作简便,科学可靠,能够作为制定相关技术标准的依据。

我国人群辐射致胃癌危险系数估算研究

目的 估算我国人群胃癌辐射致癌危险系数.方法 应用美国电离辐射效应委员会研发的日本原子弹爆炸幸存者胃癌辐射致癌危险模型,估算其辐射致癌超额相对危险和绝对危险系数.综合日本人群辐射致癌危险转移为美国人群危险的多种转移方法,确定由日本人群向我国人群危险转移模型为相乘相加混合模型（算数尺度下,相乘和相加模型权重分别为0.7和0.3）.根据我国肿瘤登记年报胃癌基线发病率,利用曲线拟合方法,估算其性别-年龄别基线发病率.综合日本人群胃癌辐射致癌危险系数及我国人群胃癌基线发病率,结合适用于我国人群的危险转移方法,估算我国人群胃癌辐射致癌危险系数.结果 估算获得我国人群胃癌辐射致癌超额相对危险系数值,男性为0.26/Sv,女性为0.64/Sv（30岁受照,60岁患癌）.受照年龄越小,患癌年龄越小此系数越大.结论 我国人群胃癌辐射致癌危险系数高于日本原子弹爆炸幸存者,二者随性别-年龄变化趋势相同.

中国人群辐射致肝癌危险系数估算研究

目的估算中国人群性别-受照年龄-患癌年龄别辐射致肝癌危险系数。方法采用中国人群肝癌性别-年龄组别基线发病率,估算中国人群肝癌性别-年龄别发病率。应用人群间危险转移方法,以日本原子弹爆炸幸存者终生寿命研究(LSS)辐射致肝癌危险模型数据为基础,采用辐射致肝癌危险转移模型(选用相乘相加混合转移模型,算数尺度下,相乘和相加模型的权重分别为0.7和0.3),估算中国人群性别-受照年龄-患癌年龄别辐射致肝癌危险系数。结果通过估算可获得中国人群性别-受照年龄-患癌年龄别辐射致肝癌危险系数;其呈现受照年龄越小,患癌年龄越小,则该危险系数越大的特征。以30岁受照,60岁患癌为例,中国男性和女性人群性别-受照年龄-患癌年龄别辐射致肝癌危险系数分别为0.29/Sv和0.32/Sv。结论通过估算获得的中国人群辐射致肝癌危险系数与日本原子弹爆炸幸存者LSS人群的有差异,但两者随性别-年龄变化趋势相同。

男性结直肠癌超额发病风险中已知危险因素的解释效果分析

[目的]结直肠癌发病性别差异较大,但原因不明,该研究拟评价男性结直肠癌发病超额风险中已知危险因素的解释比例。[方法]针对我国4个省参加结直肠癌筛查项目的参与者,开展结直肠癌危险因素分析。采用Logistic回归和超额风险解释度分析(explained share of excess risk,ERR)评价男性超额风险的危险因素解释比例。[结果]男性结直肠癌发病风险是女性的1.8倍(OR=1.80,95%CI:1.62~1.99,P<0.01);该部分超额风险可以被烟草暴露、酒精摄入、蔬菜摄入、水果摄入、畜肉摄入、粗粮摄入、体育锻炼、家族史等因素解释31.3%。[结论]男性结直肠癌超额发病风险仅有部分可被已知危险因素解释,进一步探索包括遗传易感性等在内更多的结直肠癌危险因素,对于结直肠癌一、二级预防意义重大。

上海市长宁区环境γ辐射水平与健康风险评估

目的调查上海市长宁区室内外γ辐射空气吸收剂量率,估算公众受照剂量及其健康影响。方法2022年6—12月,以网格化布点方式,根据建成年代在长宁区10个街道(镇)中各抽选12户居室,每个居室设置15个检测点。同时段在每个抽样社区中心位置抽选2条道路和1块绿地作为室外监测点,共计设置30个室外检测点。对各抽样监测点的γ辐射空气吸收剂量率开展现场检测。计算环境γ辐射所致公众人均年有效剂量当量,并评估环境γ辐射超额终生癌症风险(excess lifetime cancer risk,ELCR)。结果长宁区室内、室外的γ辐射空气吸收剂量率各监测点平均值分别为(125.80±11.72)nGy/h和(76.63±16.15)nGy/h。居室内γ辐射空气吸收剂量率高于室外(P<0.05),2000年以后建造的居室内γ辐射空气吸收剂量率低于2000年以前建造的居室(P<0.05)。室内、室外γ辐射所致公众人均年有效剂量当量平均值分别为0.617 mSv/年和0.094 mSv/年。长宁区居民居室内超额终生癌症风险均值为2.56×10-3,室外ELCR均值为4.28×10-4。结论长宁区不同区域γ辐射空气吸收剂量率有所不同,所致公众人均年有效剂量当量和ELCR均略高于全球平均水平,但处于全国正常波动区间范围内。