Puzzling elevation of blood lead levels among consumers of freshwater sportfish.

The authors evaluated lead exposure of Canadians (Montreal) who fished the nearby St. Lawrence River. From screening interviews conducted with 1,118 fishers on-site during the winter and fall of 1996, the authors selected 60 Montrealers who consumed at least one sportfish meal per week and 72 who consumed less than one sportfish meal per week. Fishers at the higher level of sportfish consumption had elevated blood lead concentrations, compared with fishers who ate little sportfish (geometric mean = 57.4 microg/l vs. 48.2 microg/l, respectively; p < .05). This result was surprising inasmuch as fish is not considered a significant source of lead. In addition to sportfish consumption, age, sex, occupation, smoking, and waterfowl consumption also showed independent associations with blood lead levels. Among frequent (i.e., > or = 1 meal/wk) consumers of sportfish, ingestion of waterfowl was associated with higher blood lead levels (geometric mean = 69.4 microg/l vs. 51.8 microg/l, respectively; p < .05); this association was not present for infrequent consumers. In multivariate analysis, the association of higher blood lead levels with sportfish consumption could be accounted for in large part by waterfowl consumption among frequent consumers of sportfish.

Mercury exposure in Montrealers who eat St. Lawrence River sportfish.

We assessed levels and determinants of mercury biomarkers among residents of Montreal and surroundings who eat sportfish from the nearby St. Lawrence River. Participants were selected from 1118 adult fishers responding to a 1996 screening questionnaire; the study sample (n=132) overrepresented respondents expected to have the greatest and the least exposure to mercury. Tissue mercury concentrations were associated with sportfish consumption: among participants who ate sportfish at least once weekly, hair geometric mean (GM)=0.82+/-2.54 microg/g and blood mercury GM=3.03+/-2.43 microg/L, compared to hair GM=0.38+/-2.28 microg/g and blood mercury GM=1.44+/-2.23 microg/L for those who ate sportfish less than once weekly. While these levels are somewhat higher than those shown for other Greater Lakes and St. Lawrence River fishers, only one participant surpassed the Canadian recommended population mercury limit of 6 microg/g for hair and 20 microg/L for blood. Consumption of several sportfish species independently explained much of the variation in measured blood mercury; the predatory species pike was the most important in multivariable regression. Coincident consumption of waterfowl, fishing during the longer summer/fall rather than the brief winter season, and fishers' age were independently associated with blood mercury. Serum selenium related neither to the level of fish consumption nor to the participants' blood mercury.

Outcomes in surgery for ovarian cancer.

OBJECTIVE: Theobjective was to determine the relationship among hospital volume of ovarian cancer surgery,academic status of institution, surgical specialty, and outcomes of care (30-day postoperative mortality, reoperation rate, and overall survival). METHODS: This population-based cohort study included all newly diagnosed ovarian cancer patients treated from 1992 to 1998 in Ontario, Canada. Hospitalization and surgical billing databases were used. Logistic regression was used to evaluate the importance of hospital type, hospital volume, surgical specialty, and surgeon volume of ovarian cancer operations on postoperative mortality, reoperation rates, and survival. RESULTS: Ovarian cancer surgery was performed on 3815 women between April 1992 and March 1998. When adjusted for age, comorbidity, acuity of the operation, and metastatic disease, no factors influenced postoperative mortality. The adjusted relative risk for reoperation within 3 months of the initial surgery showed that patients were less likely to have a repeat operation if the initial operation was done in a high- or intermediate-volume hospital (RR 0.24 95% CI 0.12-0.48, RR 0.29 95% CI 0.20-0.42, respectively), a hospital with a gynecologic oncologist (RR 0.29 95% CI 0.15-0.56), by a gynecologic oncologist (RR 0.04 95% CI 0.01-0.12) or gynecologist (RR 0.37 95% CI 0.21-0.66), or by a high-volume surgeon (RR 0.09 95% CI 0.03-0.23). The adjusted survival was improved if the initial surgery was done by a gynecologic oncologist (HR 0.70 95% CI 0.57-0.85) or gynecologist (HR 0.65 95% CI 0.53-0.79). CONCLUSIONS: There is a relationship between hospital volume and reoperation rate. Institution type only influenced reoperation rate. Statistically significant associations were found between surgical specialty and all three outcome variables. The volume of surgery performed by an individual surgeon only influenced reoperation rate. Our results are preliminary but support the need for further studies examining factors such as stage.

Fish consumption and contaminant exposure among Montreal-area sportfishers: pilot study.

A 1995 pilot study assessed sport fish consumption and contaminant exposure among Montreal-area residents fishing the frozen St. Lawrence River. Interviews conducted among 223 ice fishers met on-site were used to create an index of estimated exposure to fish-borne contaminants. A second-stage assessment of sport fish consumption and tissue contaminant burdens included 25 interviewees at the highest level of estimated contaminant exposure (of 38, or 66% of those solicited) and 15 low-exposure fishers (of 41, or 37% of those solicited). High-level fisher-consumers reported eating 0. 92+/-0.99 sport fish meals/week during the previous 3 weeks compared to 0.38+/-0.21 (P<0.05) for the low-level group. Based on the product of consumption frequency times mass of sport fish meals consumed, high-level consumers ate a mean of 18.3 kg of sport fish annually versus 3.3 kg for the low-level consumers. Tissue contaminant assessments showed significant (P<0.05) groupwise differences: 0-1 cm hair mercury (median 0.73 microgram/g for the high versus 0.23 microgram/g for the low group), lipid-adjusted plasma PCB congeners (Aroclor 1260: median 0.77 microgram/g versus 0.47 microgram/g), and lipid-adjusted plasma DDE (median 0.35 microgram/g versus 0.26 microgram/g). No participant had a hair mercury or plasma DDE concentration above Health Canada recommendations but 2/25 high-level participants (8%) had plasma Aroclor 1260 concentrations above recommended limits. The results of this pilot study suggest that a small number of Montreal-area sportfishers consume their catch as often as three times weekly and that those consuming sport fish frequently have significantly higher tissue levels of mercury, PCBs, and DDE than do infrequent consumers. On the other hand, compared to other groups in Quebec, such as the Inuit or commercial fishers on the North Shore of the Gulf of St. Lawrence, Montreal-area sportfishers eat less fish and have lower tissue concentrations of fish-related contaminants.

Contaminant exposure in Montrealers of Asian origin fishing the St. Lawrence River: exploratory assessment.

Fishing and fish consumption are widely practiced among members of certain ethnocultural groups. Informal assessment led us to ascribe high levels of consumption of locally caught sportfish to Montrealers of Asian origin and to hypothesize that their choices of species and fish organs differ from those of the majority group. An exploratory assessment of contaminant bioindicators reflective of St. Lawrence River fish consumption was conducted in late 1995 among nine Vietnamese and nine Bangladeshi Montreal sportfishers identified by community contacts. Vietnamese participants, six men and three women, were 27-70 (median 36) years of age and had immigrated to Canada 3-20 (median 7) years earlier. In contrast, the nine Bangladeshi males aged 28-41 (median 34) years had been in Canada for 2-13 (median 4) years. Bio-indicator concentrations among Bangladeshi and Vietnamese participants are compared to those found for majority-community Montreal-area high-level consumers recruited on the St. Lawrence River during winter 1995. All results are presented as the median and 90th percentile. Hair mercury concentrations were higher for both Vietnamese (1.2, 4.6 microgram/g) and Bangladeshis (1.1, 2.3 microgram/g) than for majority-community sportfishers (0.7, 1.9 microgram/g). Certain organochlorine levels, specifically total PCB (estimated by plasma Aroclor 1260), p,p'-DDT, p,p'-DDE, and B-BHC, were highest in the Bangladeshis compared to Vietnamese and to majority-community sportfishers. In contrast, plasma levels of other pesticides were low in all three groups, including mirex, chlordane, and cis-nonachlor. A correlation between plasma p,p'-DDT levels and recency of arrival in Canada was found for the Bangladeshis. These data suggest a distinct pattern of tissue organochlorines, which we postulate relates to exposure prior to arrival in Canada and perhaps to the ongoing consumption of foods (other than St. Lawrence River sportfish) specific to these groups.