Objective To investigate tile association of inicrocystin (MC) in chinking water with the incidence of colorectal cancer. Methods The study was designed as a retrospective cohort. Eight OWnSbips or tOWnS were randomly selected as tile study sites inl Haining City of Zhejiang Province, China. 408 cases of colon and rectum carcinomas diagnosed from 1977 to 1996 in the study sites were included, and a survey on types of drinking water of these patientS was conducted. Samples of different water SOurces (well, tap, river and pond) were collected separately and microcystin concentrations were datemined by indirect competitive ELISA nlethod. Results The incidence rate of colorectal cancel was significantly higher in population who drank river and pond water than those who drank well and tap water. Compared to weU water, the relative risk (RR) for colorectal cancer was 1.88 (tap), 7.94 (river) and 7.70 (pond) respectively. The positive rate (P>50pg/mL) of microcystin in samples of well, tap, river and pond water was 0, 0, 36.23% and 17.14% respectively. Tile concentration of microcystin in river and pond water was significantly tigher than that in well and tap water (P<0.01). Spearman rank conelation analysis showed that in tile study sites, tile inicrocystin concentration of river and pond water was positively associated with the incidence of colorectal cancer (rs=0.881, P<0.01). Conclusions The types of chinking water are positively associated with the incidence of colorectal cancer in the study sites, and tiffs may be related to mcrocystin COlltanination of drinking water. Further biological study is needed to snppolt tile possible Causative role of mycrocystin in carcinogenesis of colon and rectujm.

Study objective: To asses the association between alcohol consumption and the risk of colo-rectal cancer (CRC) in the Chinese population. De-sign: A population-based prospective cohort study was initiated from the colorectal cancer screening population in

PURPOSE: Colorectal cancer is a major cause of death worldwide. To reduce the incidence and mortality from rectal cancer, an individual quantitative risk-assessment model (hereafter referred to as the Attributive Degree Value) and reverse passive hemagglutination fecal occult blood test were used in a randomized, controlled, populationbased trial that was conducted in Jiashan County, People's Republic of China. METHODS: All residents of Jiashan County aged 30 years or older were enrolled in the study, and 21 townships in the county were randomized to either a screening (n=10 townships) or control (n=11 townships) group. Participants in the screened group submitted a one-article-per-slide stool sample and completed a structured risk-assessment questionnaire from which their attributive degree value was computed. According to study protocol, 4,299 participants were defined as high risk and underwent diagnostic evaluation with 60-cm flexible sigmoidoscopy and, in some cases, an additional screening with colonoscopy. RESULTS: From 1989 to 1996, cumulative mortality from colon cancer was 90 (95 percent confidence interval, 83-97) per 100,000 in the screened group and 83 (95 percent confidence interval, 76-90) per 100,000 in the control group (log-rank 1.49, P=0.222). Mortality from rectal cancer during this time was 110 (95 percent confidence interval, 102-118) per 100,000 in the screened group, which differed significantly from the control group mortality rate of 161 (95 percent confidence interval, 152-170) per 100,000 (log-rank P=0.003). CONCLUSION: Mass screening with a reverse passive hemagglutination fecal occult blood test along with an individual attributive degree value score was effective in reducing mortality from rectal cancer but not in reducing mortality from colon cancer or the incidence of colorectal cancer.

Outbreaks of paralytic snail poisoning have recently occurred in Asia, especially in China. The epidemiological charac-teristics of this disease from an outbreak in Zhoushan City, China, were recorded. Forty-two outbreaks of paralytic snail poisoning, involving 309 cases of illness, occurred from 1977 to 2001. Sixteen people (5.2%) died, 48 people (15.5%) required intubations, and 140 people (45.3%) required emergency hospital treatment as a result of these outbreaks. Outbreaks involved multiple marine snail species and occurred primarily during the summer (from June to August) on 11 islands with high population densities. Peak numbers of outbreaks and amounts of snail toxicity occurred from 1978 to 1979, from 1985 to 1987, and from 1992 to 1994. Toxicity varied depending on specimen, region, and season. The toxin involved was identified as tetrodotoxin. The data obtained in this study suggest that snails should not be eaten unless they are certified to be nontoxic.

To investigate the risk factors of colon cancer and rectal cancer. METHODS: A nested case-control study was conducted in a cohort of 64 693 subjects who participated in a colorectal cancer screening program from 1989 to 1998 in Jiashan county, Zhejiang, China. 196 cases of colorectal cancer were detected from 1990 to 1998 as the case group and 980 non-colorectal cancer subjects, matched with factors of age, gender, resident location, were randomly selected from the 64 693 cohort as controls. By using univariate analysis and mutivariate conditional logistic regression analysis, the odds ratio (OR) and its 95% confidence interval (95%CI) were calculated between colorectal cancer and personal habits, dietary factors, as well as intestinal related symptoms. RESULTS: The mutivariate analysis results showed that after matched with age, sex and resident location, mucous blood stool history and mixed sources of drinking water were closely associated with colon cancer and rectal cancer, OR values for the mucous blood stool history were 3.508 (95%CI: 1.370-8.985) and 2.139 (95%CI: 1.040-4.402) respectively; for the mixed drinking water sources, 2.387 (95%CI: 1.243-4.587) and 1.951 (95 %CI: 1.086-3.506) respectively. All reached the significant level with a P-value less than 0.05. CONCLUSION: The study suggested that mucous blood stool history and mixed sources of drinking water were the risk factors of colon cancer and rectal cancer. There was no any significant association between dietary habits and the incidence of colorectal cancer.

To study the risk factors for colorectal cancer in China. METHODS: A meta-analysis of the risk factors of colorectal cancer was conducted for 14 case-control studies, and reviewed 14 reports within 13 years which included 5034 cases and 5205 controls. Dersimonian and Laird random effective models were used to process the results. RESULTS: Meta analysis of the 14 studies demonstrated that proper physical activites and dietary fibers were protective factors (pooled OR<0.8), while fecal mucohemorrhage, chronic diarrhea and polyposis were highly associated with colorectal cancer (all pooled OR>4). The stratified results showed that different OR values of some factors were due to geographic factors or different resourses. CONCLUSION: Risks of colorectal cancer are significantly associated with the histories of intestinal diseases or relative symptoms, high lipid diet, emotional trauma and family history of cancers. The suitable physical activities and dietary fibers are protective factors.

-iodized salt group was 90 g/l, which was lower than 194g/l in the iodized salt group (u=14.673; p＜0.000), whereas the median of daily dirtary iodine intake in the two groups was 128 and 147 ug, respectivel (u=1.847; p=0.065). There was no significant correlation betwwen dietary iodine intake and urinary iodine concentration (P=0.095).

结直肠癌是常见消化道恶性肿瘤之一，谷胱甘肽转移酶（glutathione S-thransferases，GST）是体内重要的Ⅱ相解毒酶家系，参与如多环芳烃、杂环胺等致癌物质的解毒过程，GsT Mu（GsTMl）和GsT Theta（GSTTl）基因缺失会导致相应酶活性的降低[1]。本研究对象来自浙江省嘉善县，采用以人群为基础的结直肠癌随访队列，进行GSTMl和GsTTl基因多态性、饮食与结直肠癌易感性的病例对照研究。

Study objective: To asses the association between alcohol consumption and the risk of colo-rectal cancer (CRC) in the Chinese population. De-sign: A population-based prospective cohort study was initiated from the colorectal cancer screening population in Jiashan County in 1989 1990. The drinking habits of individuals were investigated with demographic information Setting; A cohort study was followed-up from 1st Mav 1990 to lst January 2001 and censored at the date of diagnosis of CRC, at death from any causes. or at 1st January 2001. whichever came first. and the person-time was com- puted Participants: Two hundred and forty two CRC patients were diagnosed during the study period and 64, 100individuals finished the follow-up Results: The distribution of sex, smoking status, occupation, edu-cation 1evel and marital status were a11 significantly different among difierent drinking habits at baseline When the above factors were adjusted, no significant association was observed between alcohol consump-tion and the risk of CRC. Exclusion of individuals diagnosed cancer less than 1 year after the examina-tion date did not alter the strength of an alcoh01 CRC relationship Further analysis in sex strata also did not show a significant relationship Conclusions Alcoh01 drinking may not be associated with a higher risk of CRC in the Chinese population.

为探讨乳腺癌发病与有机氯农药污染的关系，采片分阶段整群随机抽样的方法，按乳腺癌标化发病率高低抽取11个乡镇，再随机抽取行政村、自然村，测定再乡镇大米和土壤样品中有机氯各指标的含量，结台各乡镇的乳腺癌发病资料，进行统计分析结果表明，各乡镇的乳腺癌标化发病率存在统计学显著性差异；大米中&-HcH、y-HcH、五氯酚钠以及土壤的&-HcH含量在各乡镇间有显著性差异；乳腺癌标化发病率与大米中PP'-DDD含量呈负相关，相关系数为-0.609，说明经过近20年的降解过程，DDT的衍生物含量最终以PP'-DDD居多，并且乳腺癌标化发痛率与大米中PP'-DDD含量呈负相关。