DOI: 10.5061/dryad.pc866t23m
title: Chronic low-dose exposure to chlorpyrifos reduces lifespan in a wild fish by accelerating aging

description: Low-concentration chemicals are widespread in the environment,
 but exploration of the effects of their chronic
 exposures on animal lifespan in the wild is
 limited. Field investigations showed that fish
 populations of Culter dabryi with chronic low-dose
 chlorpyrifos loads had shortened telomeres and truncated
 age structures. Laboratory experiments confirmed that chronic low-dose
 chlorpyrifos exposure induced telomere degradation and reduced
 survival in a dose- and physiological age-dependent manner, whereas acute
 high-dose exposure did not. Together, these studies
 provide evidence that chronic low-level chlorpyrifos exposure
 reduces lifespan and population viability in a wild fish
 by accelerating physiological aging. Given the pervasive nature of low
 concentrations of pesticides in the environment and the conserved
 mechanisms of aging across vertebrates, these findings raise concerns
 about the potential long-term risks to longevity of
 pesticides, even at low doses.
description: This repository contains the code and data to run the analyses
 from K Huang <em>et al.</em>, “Chronic low-dose exposure to
 chlorpyrifos reduces lifespan in a wild fish by accelerating aging”.  We
 performed a four-year field survey in three adjacent lakes with different
 levels of pesticide burdens, namely Niushan Lake (NSL, reference lake),
 West Liangzi Lake (WLL), and East Liangzi Lake (ELL), to characterize the
 aging phenotypes (e.g., telomere degradation, lipofuscin deposition,
 reduced lifespan, and truncated age structures) of <em>C.
 dabryi</em> populations. We further measured the concentrations of
 96 pesticides in these fish, investigated the associations between
 pesticide contamination and fish aging, and identified the main causal
 agent. Laboratory chronic exposure experiments were conducted to confirm
 the chronic aging effects of pesticides observed in the field, and the
 possible acute exposure was ruled out.
description: # Chronic low-dose exposure to chlorpyrifos reduces lifespan in a wild
 fish by accelerating aging
 [https://doi.org/10.5061/dryad.pc866t23m](https://doi.org/10.5061/dryad.pc866t23m) The dataset (ady4727_Data.xlsx) includes 8 spreadsheets: 1.Body weight distribution data: Body weight distribution in wild *C. dabryi* populations across Niushan, West Liangzi, and East Liangzi Lakes from 2020 to 2023. 2.Body length distribution data: Body length distribution in wild *C. dabryi* populations across Niushan, West Liangzi, and East Liangzi Lakes from 2020 to 2023. 3.Age structure data: Numbers of individuals across different age classes in wild *C. dabryi* populations in various quarters from 2020-2023. 4.Field pesticide_aging data: Pesticide concentrations and biological aging parameters in wild *C. dabryi* populations across Niiushan, West Liangzi and East Liangzi Lakes from 2020 to 2023. 5.Chronic exposure data: Pesticide concentrations, relative telomere lengths and lipofuscin depositions after chronic exposure to environmental concentrations of chlorpyrifos. 6.Chronic exposure survival data: Mortality statistics of *C. dabryi* during chronic exposure to environmental concentrations of chlorpyrifos. 7.Acute exposure data: Pesticide concentrations and relative telomere lengths following acute high-concentration chlorpyrifos exposure. 8.Acute exposure survival data: Mortality statistics following acute high-concentration chlorpyrifos exposure in *C. dabryi*. ## Description of the data and file structure ### DATA-SPECIFIC INFORMATION FOR: Body weight distribution data Number of variables: 4 Description: This data file provides the percentage distributions of *C. dabryi* across different body weight intervals, collected from three lakes (Niushan Lake, West Liangzi Lake, and East Liangzi Lake) between 2020 and 2023. Further details on the data and methods are provided in the corresponding manuscript and supplementary materials. Variable list: Weight Group: The body weight distributions of *C. dabryi* were categorized into consecutive 10 g intervals. Niushan Lake: The percentage that the number of individuals within this body weight interval accounts for in the Niushan Lake *C. dabryi* population. West Liangzi Lake: The percentage that the number of individuals within this body weight interval accounts for in the West Liangzi Lake *C. dabryi* population. East Liangzi Lake: The percentage that the number of individuals within this body weight interval accounts for in the East Liangzi Lake *C. dabryi* population. ### DATA-SPECIFIC INFORMATION FOR: Body length distribution data Number of variables: 4 Description: This data file provides the percentage distributions of *C. dabryi* across different body length intervals, collected from three lakes (Niushan Lake, West Liangzi Lake, and East Liangzi Lake) between 2020 and 2023. Further details on the data and methods are provided in the corresponding manuscript and supplementary materials. Variable list: Length Group: The body length distributions of *C. dabryi* were categorized into consecutive 10 mm intervals. Niushan Lake: The percentage that the number of individuals within this body length interval accounts for in the Niushan Lake *C. dabryi* population. West Liangzi Lake: The percentage that the number of individuals within this body length interval accounts for in the West Liangzi Lake *C. dabryi* population. East Liangzi Lake: The percentage that the number of individuals within this body length interval accounts for in the East Liangzi Lake *C. dabryi* population. ### DATA-SPECIFIC INFORMATION FOR: Age structure data Number of variables: 11 Description: This data file includes the numbers of *C. dabryi* individuals across different age classes, sampled seasonally from three lakes (Niushan Lake, West Liangzi Lake, and East Liangzi Lake) between 2020 to 2023. Further details on the data and methods are provided in the corresponding manuscript and supplementary materials. Variable list: Year: Years when field population surveys were conducted. Season: Quarters of field population surveys conducted. Site: Study areas, including Niushan Lake, West Liangzi Lake and East Liangzi Lake Sex: M = Male; F = Female. Age-1 count: Numbers of Age-1 Individuals. Age-2 count: Numbers of Age-2 Individuals. Age-3 count: Numbers of Age-3 Individuals. Age-4 count: Numbers of Age-4 Individuals. Age-5 count: Numbers of Age-5 Individuals. Age-6 count: Numbers of Age-6 Individuals. Age-7 count: Numbers of Age-7 Individuals. ### DATA-SPECIFIC INFORMATION FOR: Field pesticide_aging data Number of variables: 28 Description: This data file includes pesticide concentrations in *C. dabryi* across different seasons (2020-2023) from three lakes (Niushan Lake, West Liangzi Lake, East Liangzi Lake). It also includes lipofuscin deposition levels in 3-year-old fish and relative telomere lengths across different age groups. Further details on the data and methods are provided in the corresponding manuscript and supplementary materials. Variable list: Fish ID: Unique identifiers of fish. Year: Years when field population surveys were conducted. Season: Quarters of field population surveys conducted. Site: Study areas, including Niushan Lake, West Liangzi Lake and East Liangzi Lake. Tissue: Tissues used for pesticide detection and biological measurements. Sex: M=Male; F=Female. Age: Ages of fish used for pesticide detection and biological measurements. RTL: Relative telomere length of *C. dabryi* across different age classes. Lipofuscin Area: Lipofuscin deposition area in 3 years old fish during the 2021-2023 field investigation. Chlorpyrifos: Chlorpyrifos concentrations in liver (ng/g). Prometryn: Prometryn concentrations in liver (ng/g). Difenoconazole: Difenoconazole concentrations in liver (ng/g). Carbendazim: Carbendazim concentrations in liver (ng/g). Dichlorvos: Dichlorvos concentrations in liver (ng/g). Acetamiprid:concentrations in liver (ng/g). Atrazine: Atrazine concentrations in liver (ng/g). Chlorantraniliprole: Chlorantraniliprole concentrations in liver (ng/g). Azoxystrobin: Azoxystrobin concentrations in liver (ng/g). Myclobutanil: Myclobutanil concentrations in liver (ng/g). Isofenphos-methyl: Isofenphos-methyl concentrations in liver (ng/g). Buprofezin: Buprofezin concentrations in liver (ng/g). Thiamethoxam: Thiamethoxam concentrations in liver (ng/g). Avermectin: Avermectin concentrations in liver (ng/g). Pretilachlor: Pretilachlor concentrations in liver (ng/g). Paclobutrazol: Paclobutrazol concentrations in liver (ng/g). Metolachlor: Metolachlor concentrations in liver (ng/g). Kresoxim-methyl : Kresoxim-methyl concentrations in liver (ng/g). Butachlor: Butachlor concentrations in liver (ng/g). NA = not applicable &lt; MQL= Less than the Method Quantification Limit ### DATA-SPECIFIC INFORMATION FOR: Chronic exposure data Number of variables: 8 Description: This data file presents liver lipofuscin levels, and relative telomere lengths in age-2 and age-3 *C. dabryi* (from Niushan and East Liangzi Lakes) after 16-week chronic exposure to chlorpyrifos. Further details on the data and methods are provided in the corresponding manuscript and supplementary materials. Variable list: Group: Each concentration group included three replicate tanks (1, 2, 3) for the exposure experiment, and in each tank two fish were sampled. Site: Sources of experimental fish used for exposure, including Niushan and East Liangzi Lakes. Age: Ages of experimental fish used. Exposure concentration: Three concentrations (0, 10 and 50 ng/L) were established. Exposure Duration: The chronic exposure lasted for 16 weeks. Tissue: Tissues used for pesticide detection and biological measurements. RTL: Relative telomere lengths after chronic exposure. Lipofuscin Area: Lipofuscin deposition area after chronic exposure. ND = Not Detected ### DATA-SPECIFIC INFORMATION FOR: Chronic exposure survival data Number of variables: 7 Description: This data file contains mortality data for 2- and 3-year-old *C. dabryi* (from Niushan and East Liangzi Lakes) during a 16-week chronic exposure to environmentally relevant concentrations of chlorpyrifos. Further details on the data and methods are provided in the corresponding manuscript and supplementary materials. Variable list: Site: Sources of experimental fish used for exposure, including Niushan Lake and East Liangzi Lake. Age: Ages of the experimental fish used. Exposure Duration: The chronic exposure lasted for 16 weeks. Total Number: Numbers of test fish per treatment group. 0 ng/l: Mortality count in control group. 10 ng/L: Mortality count in 10 ng/L group. 50 ng/L: Mortality count in 50 ng/L group. ### DATA-SPECIFIC INFORMATION FOR: Acute exposure data Number of variables: 8 Description: This data file includes mortality data for 2- and 3-year-old *C. dabryi* (from Niushan and East Liangzi Lakes) following a 96-hour acute exposure to high concentrations of chlorpyrifos. Further details on the data and methods are provided in the corresponding manuscript and supplementary materials. Variable list: Group: Each concentration group included three replicate tanks (1, 2, 3). Site: Sources of experimental fish used for exposure including Niushan Lake and East Liangzi Lake. Age: Ages of the experimental fish used. Exposure concentration: Six exposure concentrations (0, 100, 200, 400, 800, and 1600 g/L) were established for each experiment. Exposure Duration: 96 hours. Tissue: Tissue used for pesticide detection and biological measurements. Tissue concentration: Liver chlorpysifos concentrations after acute exposure. RTL: Relative telomere lengths after acute exposure. ND = Not Detected ### DATA-SPECIFIC INFORMATION FOR: Acute exposure survival data Number of variables: 7 Description: This data file includes mortality data for 2- and 3-year-old *C. dabryi* (from Niushan and East Liangzi Lakes) following a 96-hour acute exposure to high concentrations of chlorpyrifos. Further details on the data and methods are provided in the corresponding manuscript and supplementary materials. Variable list: Group: Each concentration group included three replicate tanks (1, 2, 3). Site: Sources of experimental fish used for exposure, including Niushan Lake and East Liangzi Lake. Age: Ages of the experimental fish used. Exposure concentration: Six exposure concentrations (0, 100, 200, 400, 800, and 1600 g/L) were established for each experiment. Exposure Duration: 96 hours. Total Number of Fish: Numbers of fish per treatment group. Mortality Count: Mortality count per tank after acute exposure. ### Code/Software All analyses were performed in R version 4.3.2 and the scripts are provided in the ady4727_Code.R file. This code analyzes experimental (non-simulated) data from different sheets of an Excel file using appropriate statistical models (linear, mixed-effects, and binomial GLMs) to test effects of site, time, age, and exposure. It then generates publication-ready figures showing model-based predictions with confidence intervals alongside raw data.