else if( id == effect_toxin_buildup ) {
        // Loosely based on toxic man-made compounds (mostly pesticides) which don't degrade
        // easily, leading to build-up in muscle and fat tissue through bioaccumulation.
        // Symptoms vary, and many are too long-term to be relevant in C:DDA (i.e. carcinogens),
        // but lowered immune response and neurotoxicity (i.e. seizures, migraines) are common.

        if( in_sleep_state() ) {
            return;
        }
        // Modifier for symptom frequency.
        // Each symptom is twice as frequent for each level of intensity above the one it first appears for.
        int mod = 1;
        switch( intense ) {
            case 3:
                // Tonic-clonic seizure (full body convulsive seizure)
                if( one_turn_in( 3_days ) && !has_effect( effect_valium ) ) {
                    add_msg_if_player( m_bad, _( "You lose control of your body as it begins to convulse!" ) );
                    time_duration td = rng( 30_seconds, 4_minutes );
                    add_effect( effect_motor_seizure, td );
                    add_effect( effect_downed, td );
                    add_effect( effect_stunned, td );
                    if( one_in( 3 ) ) {
                        add_msg_if_player( m_bad, _( "You lose consciousness!" ) );
                        fall_asleep( td );
                    }
                }
                mod *= 2;
            /* fallthrough */
            case 2:
                // Myoclonic seizure (muscle spasm)
                if( one_turn_in( 2_hours / mod ) && !has_effect( effect_valium ) ) {
                    std::string limb = random_entry<std::vector<std::string>>( {
                        translate_marker( "arm" ), translate_marker( "hand" ), translate_marker( "leg" )
                    } );
                    add_msg_if_player( m_bad, string_format(
                                           _( "Your %s suddenly jerks in an unexpected direction!" ), _( limb ) ) );
                    if( limb == "arm" ) {
                        mod_dex_bonus( -8 );
                        recoil = MAX_RECOIL;
                    } else if( limb == "hand" ) {
                        if( is_armed() && can_unwield( weapon ).success() ) {
                            if( dice( 4, 4 ) > get_dex() ) {
                                put_into_vehicle_or_drop( *this, item_drop_reason::tumbling, { remove_weapon() } );
                            } else {
                                add_msg_if_player( m_neutral, _( "However, you manage to keep hold of your weapon." ) );
                            }
                        }
                    } else if( limb == "leg" ) {
                        if( dice( 4, 4 ) > get_dex() ) {
                            add_effect( effect_downed, rng( 5_seconds, 10_seconds ) );
                        } else {
                            add_msg_if_player( m_neutral, _( "However, you manage to keep your footing." ) );
                        }
                    }
                }
                // Atonic seizure (a.k.a. drop seizure)
                if( one_turn_in( 2_days / mod ) && !has_effect( effect_valium ) ) {
                    add_msg_if_player( m_bad,
                                       _( "You suddenly lose all muscle tone, and can't support your own weight!" ) );
                    add_effect( effect_motor_seizure, rng( 1_seconds, 2_seconds ) );
                    add_effect( effect_downed, rng( 5_seconds, 10_seconds ) );
                }
                mod *= 2;
            /* fallthrough */
            case 1:
                // Migraine
                if( one_turn_in( 2_days / mod ) ) {
                    add_msg_if_player( m_bad, _( "You have a splitting headache." ) );
                    mod_pain( 12 );
                }

                break;
        }